Overview
iRelease has been made obsolete. If you’re interested in the capabilities, we suggest looking at our Deck Topside
iRelease is a rugged, handheld unit that’s used as part of a Lightweight Command Unit (LCU) setup on the back deck to test, load and release our legacy range of ORT and DORT acoustic release transponders.
At a glance
- Use it to test and control legacy ORT and DORT acoustic releases
 - Compatible with legacy LCU dunking systems (replaces obsolete Psion unit)
 - Handheld design, battery powered, rechargeable
 - Splash-proof and rugged; designed for the back deck
 - Easy-to-use five-button interface
 
Specifications table
| Feature | Type 8315 | |
|---|---|---|
| Case | Rugged polypropylene copolymer case with styrenic over mould shock protection | |
| Keypad | Sealed 5 key navigation pad | |
| Display | 320 x 240 sunlight readable LED display | |
| Connections | USB | Splash-proof mini-USB Type B | 
| Serial | 9-way D-type (male) | |
| Charging | USB to PC or USB to wall adaptor | |
| Internal flash memory | 1 GB | |
| Battery | Li-ion 3.7 V 1,300 mAh (typical) | |
| Battery life | Normal (screen on) | >5 hours (screen automatically turns off after a selectable period) | 
| Idle (screen off) | >12 hours (press a key or ‘shake to wake’ to turn screen back on) | |
| Off | >3 months (press a key to wake) | |
| Off for shipping | >1 year (requires USB connection to wake-up) | |
| Operating temperature | -10 to 55°C | |
| Storage temperature | -10 to 55°C | |
| Dimensions (length x width x depth) | 194 x 84 x 40 mm | |
| weight | 0.8 kg | 
Datasheets
Manuals and quick start guides
What's possible
You need transponders to be tough, reliable and easy to work with. RT 6-3000 meets these requirements.
Part of our range of acoustic releases, RT 6-3000 combines our extensive mechanical design track record and many years of subsea mooring experience with the flexibility of our 6G platform. The result is an enhanced battery life and, perhaps most significantly, compatibility with our Ranger 2 USBL family.
Deploy. Track. Locate. Recover.
With RT 6-3000, you can use your Ranger 2 USBL to deploy, track, locate and command the instrument – removing the need for a separate topside unit.
If you don’t have access to a Ranger 2 USBL, our rugged and lightweight Deck Topside with an over-the-side dunker is all you need to configure and command your RT 6-3000s.
RT 6-3000s are used to anchor oceanographic moorings to the seabed. However, their compact size and compatibility with Ranger 2 makes them ideal for incorporation into instrument frames or lowered platforms to enable deployment of sub-system packages. Depth rated to 3,000 m, the maximum slant range for operation is dependent on the noise environment and topside used, but ranges to 4,500 m are achievable.
A battery disconnect fob is located on the transducer and uses an internal magnetic switch to electronically disconnect the battery when not in use. This means you don’t have to open the unit to manually disconnect the battery, saving time and reducing the risk of incorrect re-assembly.
Standard features include a Working Load Limit (WLL) of 1,275 kg (at 4:1) and the same trusted spring-assisted release mechanism used on thousands of Sonardyne transponders globally for many years. RT 6-3000 is compatible with our standard tandem and high-load release frames for scenarios requiring a higher WLL.
Speak to us about your requirements as custom frames are also an option.
Acoustics
•	Medium Frequency (19-34kHz) band, Wideband 2
•	Omni-directional transducer. Track it all the way to the surface
•	Sonardyne Wideband 2 signal architecture supporting over 300 unique addresses
•	Compatible with any Ranger 2 USBL system and Deck Topside
Design
•	700 x 142 mm, 15 kg weight in water
•	Aluminium bronze, duplex stainless steel construction. ROHS compliant
•	Configured with iWand hand-held acoustic transponder test and configuration device
•	Compatible with our standard tandem and high-load release frame
Performance
•	3,000 m depth rated
•	4,500 m working range
•	>32 months battery life; alkaline battery
•	1,275 kg Working Load Limit
•	Secure and robust two-way acoustic communications. Only release what you want to release
Ownership
•	What’s in the box: RT 6-3000, shackles, manual on USB
•	Warranty: 1 year return to Sonardyne service centre
•	ITAR Controlled: no
•	UK Export Licence: not required
Specifications
| Feature | Type 8320-3411 | 
|---|---|
| Depth Rating | 3,000 m* | 
| Maximum Slant Range | 4,500 m | 
| Operating Frequency | MF (20–34 kHz) | 
| Transducer Beam Shape | Hemispherical | 
| Transmit Source Level (dB re 1 µPa @ 1 m) | 186 dB | 
| Tone Equivalent Energy (TEE) | 192 dB | 
| Receive Threshold (dB re 1 µPa) | <90 dB | 
| Working Load Limit (4:1) | 1,275 kg | 
| Proof Load | 2,550 kg | 
| Breaking Load | 5,100 kg | 
| Maximum Safe Release Load | 1,700 kg | 
| Battery Life (Alkaline) | >32 months active | 
| Inclinometer Accuracy | ±5° | 
| Surface Unit | Deck Topside, Ranger 2 USBL | 
| Mechanical Construction | Aluminium bronze and duplex stainless steel | 
| Operating Temperature | -5 to 40°C | 
| Storage Temperature | -20 to 55°C | 
| Dimensions (Length x Diameter) | 700 x 142 mm (27.5 x 5.6”) | 
| Weight in Air/Water | 20/15 kg | 
| Standards | CE Marked to EN-60945, EN-61010 | 
| Options | Shallow Water Deck Kit (Deck Topside) – 602-0175 | 
| Mid Water Deck Kit (Deck Topside) – 602-0179 | |
| Heavy Duty Release Frames (7.5 T, 15 T and 25 T) | |
| *RT 6-3000 is pressure rated to 4,000 m; however, due to operating range constraints of MF, its use at depths greater than 3,000 m is not recommended. | 
Frequently asked questions
What is an Acoustic Release and how does it work?
Why isn’t serial communication available using the iWand in RT 6 Dunker Mode?
6G Terminal Lite Range Test
What is the safe working load for different RT 6 products?
What should I use instead of an ORT and DORT?
How to change the battery on an RT 6-3000 or RT 6000
How to load the release on an RT 6-3000 and RT 6-6000
Which RT 6 is correct for my operations?
How to release an RT 6 acoustic release transponder using Ranger 2
How long can an RT 6-3000 and RT-6 6000 be deployed for?
Deployment
STP files
Software and control hardware
Manuals and quick start guides
Did you know?
RT 6-3000 can be used with our Ranger 2 USBL family or Deck Topside
Entry level – next level
What's possible
The RT 6-1000 is the versatile acoustic release transponder for your subsea operations. It can be commanded from multiple sources, including the Deck Topside, an Android app, or any Ranger 2 USBL system. This flexibility allows you to easily deploy, track, locate and retrieve your seabed equipment and ocean sensors.
One of the key advantages of the RT 6-1000 is its depth rating of 1,000 metres and weight load limit of 150 kg. This depth and payload capacity make it an ideal choice for scientists, surveyors, and military personnel who require a reliable and enduring solution for their underwater applications.
The RT 6-1000 is compatible with Sonardyne’s Ranger 2 USBL tracking systems, which are widely used on survey vessels around the world. This integration allows for seamless deployment, tracking, and retrieval of your equipment. No access to Ranger 2? No problem, the RT 6-1000’s NFC capability enables setup and control via its Android app or a dedicated Deck Topside unit.
Deploy. Track. Locate. Recover
At a glance
- The reliable choice to deploy, leave and recover seafloor equipment and sensors
 - 1,000 metre depth rating; twice that of similar low-cost acoustic release transponders
 - Tested, loaded, commanded and released using Deck Topside
 - Also works with any Ranger 2 USBL to track it and activate it
 - >13-month battery life means less time servicing it and more time using it
 - 150 kg Working Load Limit to support your sensors and instruments
 - Optional rope canister for heavy lifting
 
The RT 6-1000 offers impressive endurance, with a battery life of up to 13 months, making it well-suited for long-term deployments and year-long surveys. Its screw-off release mechanism ensures reliable recovery of the transponder and your equipment.
An optional rope canister attachment allows you to quickly and easily raise items left on the seabed, such as tools, cables and salvage. The canister deploys a high-strength rope as the transponder ascends, providing a convenient means of retrieval.
Acoustic
•	Medium Frequency (20-34 kHz) band.
•	Omni-directional transducer. Track it all the way to the surface
•	Sonardyne Wideband 2 signal architecture supporting over 300 unique addresses. Perfect for very large surveys involving multiple moorings close to each other
Performance
•	1,000 m depth rated
•	>13 months battery life; alkaline battery
•	150 kg Working Load Limit
•	Compatible with Ranger 2 USBL systems
•	Secure and robust two-way acoustic Communications. Only release what you want to release
Design
•	450 mm x 65 mm (max dia. 100 mm), 500 grams weight in water
•	Field proven screw-off release mechanism
•	NFC for setup using Android app
•	Optional rope canister for lifting heavy items
•	Plastic, super duplex stainless steel and anodised aluminium construction. ROHS compliant
Ownership
•	Warranty: one year return to Sonardyne service centre
•	ITAR Controlled: No
•	UK Export Licence: Not required
•	What’s in the box: RT 6-1000, shackles, release nuts (x10), manual on USB
Specifications table
| Feature | Type 8327 | |
|---|---|---|
| Depth rating | 1,000 m | |
| Operating frequency | MF (20–34 kHz) | |
| Transducer beam shape | Hemispherical | |
| Transmit source level (dB re 1 µPa @ 1 m) | 187 dB | |
| Tone Equivalent Energy (TEE) | 193 dB | |
| Receive threshold (dB re 1 µPa) | <100 dB | |
| Working load limit (4:1) | 150 kg | |
| Proof load | 300 kg | |
| Breaking load | 600 kg | |
| Maximum safe release load | 150 kg | |
| Battery life (alkaline) | >13 months | |
| Inclinometer accuracy | ±5° | |
| Mechanical construction | Anodised aluminium alloy, plastic and super duplex stainless steel | |
| Operating temperature | -5 to 40ºC | |
| Storage temperature | -20 to 55ºC | |
| Maximum dimensions (length x diameter) | 450 x 65 mm | |
| Weight in air/water | 2.0/0.5 kg | |
| Standards | CE Marked to EN-60945, EN-61010 | |
| Options | Part number | |
| Shallow Water Deck Kit (Deck Topside) | 602-0175 | |
| Rope Canister | 70 m (250 kg WLL) | 641-0673 | 
| 120 m (250 kg WLL) | 641-3265 | |
| 160 m (150 kg WLL) | 641-0080 | |
| Release Nut | 830-0073 (note: 10 nuts supplied with each new RT 6-1000)  | 
|
| Shackle (bridle) | 231-0140 | |
| Deployment rope (bridle) | 231-0351 | 
Frequently asked questions
What is an Acoustic Release and how does it work?
Why isn’t serial communication available using the iWand in RT 6 Dunker Mode?
RT 6-1000 NFC connection and operating information
6G Terminal Lite Range Test
How long can an RT 6-1000 be deployed for?
What is the safe working load for different RT 6 products?
How do I mark where my RT 6-1000 is deployed?
No NFC device is available to connect the battery
Why can’t my NFC device contact the transponder?
How to change the battery in an RT 6-1000
Which RT 6 is correct for my operations?
Why should I use a rope canister and what is it?
Where can I find the RT6 release app
How to release an RT 6 acoustic release transponder using Ranger 2
How to use a rope canister
How to recover an RT 6-1000
Deployment
STP files
Software and firmware
Software and control hardware
Datasheets
Manuals and quick start guides
Did you know?
RT 6-1000 can be used with our Ranger 2 USBL family or Deck Topside
What is possible
Ranger 2 comes with an impressive list of features including our award-winning 6G (sixth generation) acoustic hardware platform and Sonardyne Wideband 2 digital signal architecture. It provides stable and repeatable acoustic position referencing for your ship’s DP system, including those from GE, Kongsberg, MT, Navis, Thrustmaster and Wärtsilä.
As your needs grow and become more complex, bolt-on software packs unlock additional capability and protect your investment. Take the DP pack and enable your acoustic ranging to be aided by our inertial navigation technology (DP-INS). Add the robotics pack and commanding a swarm of up to 99 AUVs is at your fingertips.
Ranger 2 can do even more, it also supports robust two-way data telemetry, allowing you to control our range of seafloor deployed, long-endurance sensors and recover your all-important data.
Track everything, in any depth, from any vessel
Why choose it?
- Tracks multiple targets to 11 km;
 - Compatible with all makes of DP system – GE, Kongsberg, MT
 - System accuracy: when fully optimised it will deliver 0.04% of slant range
 - Works with a global inventory of pre-deployed Sonardyne 6G hardware
 - Configurations available for USV and temporary vessel installations
 - Valuable features included as standard
 - Bolt-on packs available for growth with your operations and ambitions
 - Developed and supported by a company with over 50 years of experience in innovative underwater technology
 
Learn more about Ranger 2 USBL
The kit
Transceivers
Our High Performance Transceiver (HPT), is available in a range of different designs to suit your operations whether they are in deep or shallow water or over a long layback.
HPT 5000 / 7000 are acoustic and telemetry transceivers designed for use with Ranger 2 USBL system. HPT 5000 enables targets to be tracked over a wide range of water depths; HPT 7000 is optimised for noisy DP drilling or construction vessels and in deep water.
HPT 5000 offers full hemispherical acoustic coverage so is a popular choice for tracking multiple targets (ROVs, AUVs, towfish, seafloor sensors) over a wide range of depths and elevations. The unit is also suitable for dynamic positioning reference on survey, research and offshore support vessels.
HPT 7000 is engineered for ultra-deepwater operations, tracking targets far below (rather than to the side of) a vessel, and for high vessel noise operating environments such as those typical of DP, drilling and construction where activity from thrusters is liable to cause signal interference.
If you need a solution for a vessel of opportunity, our pre-calibrated, all-in-one Gyro USBL transceiver is perfect. Lighter, smaller and just as capable, our second-generation Gyro USBL transceiver works seamlessly with Ranger 2 to track the position of your subsea targets from a USV, vessel of opportunity or from a pipelay vessel’s stinger over extreme ranges.
- All-in-one instrument; combined 6G acoustic transceiver and AHRS
 - Choose between standard or ‘plus’ variants to suit your project’s specifications
 - Optimises the performance of Ranger 2; eliminates lever arm offsets, pole bending and ship flexing errors
 - Calibrated in-water before delivery – saving you time; install it and go to work
 
Transponders
The flexibility of the Ranger 2 family is further extended by our range of transponders to support a wide variety of your operations. WMT is a high-power transponder capable of operations to 7,000 m, while AvTrak 6 is our most capable acoustic vehicle instrument, combining the functions of a USBL transponder, LBL transceiver and modem for demanding applications such as AUV command and control.
Discover Ranger 2 in action
A new world of multi-robot ocean exploration
Read moreOptimising shallow water positioning for combined magnetometer and hydrographic surveys
Read moreLong-endurance AUV development with shallow water simplicity
Read morePerformance
•	 Up to 0.04% of slant range system accuracy
•	 Up 99 targets tracked, sequentially
•	 Up to 11,000 m tracking range (LMF)
•	 1 Hz position update rate
•	 Supports all industry standard DP telegrams
•	 Supports acoustically aided INS
Acoustics
•	 MF frequency (20–34 kHz) or LMF (14-19.5 kHz)
•	 Compatible with a wide range of 6G transponders
•	 Supports Sonardyne Messaging Service for data exchange up to 9,000 bps
•	Sonardyne Wideband 2 acoustics for reliable performance in both shallow and deep-water environments
Ownership
•	 ITAR Controlled: No
•	 Warranty: 1 year return to Sonardyne service centre
•	 UK Export Licence: Required
•	 What’s in the box: HPT 5000 / 7000 / Gyro USBL, deck cables, software, manual
Overview
•	 Can be used for both survey and construction phases
•	 Configurable to work in the LMF band enabling you to track targets to beyond 11 km
•	 Supports complex tracking scenarios such as structures and vehicles with multiple transponders and multiple remote offsets
Specifications table
| Feature | Specification | 
|---|---|
| Design | The most powerful USBL system on the market | 
| Incorporates 30 years of USBL innovation and know-how | |
| Recommended for installation on large vessels and USVs | |
| Global vessel track record; offshore, research, cable-lay, salvage and naval | |
| Shares common platform with other Sonardyne USBLs | |
| Performance | Up to 0.04% of slant range system accuracy | 
| Up to 99 targets tracked, simultaneously | |
| Up to 11,000 m tracking range (LMF) | |
| 1 Hz position update rate | |
| Support all industry standard DP telegrams | |
| Supports acoustically-aided INS | |
| Acoustics | MF frequency (20-34 kHz) or LMF (14-19.5 kHz) | 
| Sonardyne Wideband 2 digital acoustics for reliable performance in both shallow and deep environments | |
| Supports Sonardyne Messaging Service for data exchange up to 9,000 bps | |
| Compatible with a wide range of 6G transponders | 
Frequently asked questions
Planning 6G beacon deployments
CASIUS calibration recommendations
What is a USBL and how does it work?
How to use Auto Discover to scan the water for unknown transponder addresses
How to format the sound speed profile for Marksman and Ranger 2
How to use HPR418BCD telegrams for DP
How to mount and extract an ISO image
How to track an underwater locator beacon
How to Compensate for Responder Latency
How to set up an SSB_LBP Telegram
Marksman/Ranger 2 DP INS indicator sequence explained
How to create an alarm to warn that the transceiver deployment pole has been left deployed
How to import waypoints into Ranger 2
How to enter Transceiver & Lodestar Offsets for Optimised USBL
Frequency management is obsolete. Here’s why.
How to set up Responder Mode
Opening a .DJF file on Sonardyne De Novo Job Viewer
How to Skip Telemetry Options in Rangers 2 and Marksman LUSBL
What should I do if my Sonardyne security dongle expires or reports a problem?
How to Capture a cef in Marksman and Ranger 2
How to download or upload files using Filezilla
Why am I getting old / incorrect data from my GyroCompatt 6+?
How to turn on a Lodestar Gyro Compatt using Ranger 2 or Fusion 2
I’m outputting a GGA from Fusion 2 / Ranger 2 to NaviPac but the position isn’t appearing in the correct location?
Health check for your acoustic system
How do I mark where my RT 6-1000 is deployed?
Will Compatt 6+ work with Ranger 2 and Marksman?
The transponder isn’t replying to interrogation or commands
Can I get USBL position updates from my AUV with Ranger 2/ Mini-Ranger 2?
How quickly can I start tracking beacons with Ranger 2?
Has anyone ever installed an echosounder and Ranger 2 USBL transceiver directly beside each other? Would this work?
Can I perform a USBL verification in shallow water without an ROV to deploy or recover the beacon?
How do USBLs work?
Which USBL Deployment Machine is most suitable for my vessel?
Advantages of using Ranger 2 for ROV tracking
When to use Depth Aiding
What’s new in Micro Ranger 2?
What to consider when mounting acoustic transducers
What acoustic address should I use for my USBL transponder
What do my CASIUS results tell me about my USBL calibration
Calibration tips for Ranger 2 USBL systems
How to align Gyro USBL to the vessel frame of reference
How to interface Ranger 2 into a 3rd party survey system
How can an uncrewed system interact with Ranger 2 software?
How can I synchronise a clock on my AUV to a GNSS reference using Ranger 2?
What is Telemetry Tracking, and why would I need it?
How to release an RT 6 acoustic release transponder using Ranger 2
How to set up an update rate in Ranger 2
How to set the operating range in Ranger 2
How to configure sound speed in Ranger 2
Ranger 2 – How to release an RT6 acoustic release transponder
Software and firmware
Software and control hardware
How to enter Transceiver & Lodestar Offsets for Optimised USBL
How to set up Responder Mode
Opening a .DJF file on Sonardyne De Novo Job Viewer
What’s new in Micro Ranger 2?
What do my CASIUS results tell me about my USBL calibration
How to release an RT 6 acoustic release transponder using Ranger 2
How to set up an update rate in Ranger 2
Top tips
How to Skip Telemetry Options in Rangers 2 and Marksman LUSBL
What should I do if my Sonardyne security dongle expires or reports a problem?
How to Capture a cef in Marksman and Ranger 2
How to download or upload files using Filezilla
Which USBL Deployment Machine is most suitable for my vessel?
Advantages of using Ranger 2 for ROV tracking
When to use Depth Aiding
What to consider when mounting acoustic transducers
What acoustic address should I use for my USBL transponder
Calibration tips for Ranger 2 USBL systems
How to align Gyro USBL to the vessel frame of reference
Datasheets
Manuals and quick start guides
Technical bulletin
Origin 65 holds the key to help unlock Gulf of Mexico loop current eddy mysteries
The Gulf of Mexico is home to the highly energetic ocean circulation feature known as the Gulf Loop Current System (LCS). This current system influences all ocean processes in the gulf, characterised by highly disruptive Loop Current Eddy (LCE) events. LCEs are rings of warm water which rotate at speeds of up to four knots in a clockwise direction, measuring approximately 100-200 km in diameter, reaching down to depths of 500–1,000 m, and breaking away from the extended Loop Current around every 8-9 months. Loop Current Eddy events have serious implications for a great range of natural and human activities, from ecosystem dynamics and hurricane intensification to fishing operations and oil and gas exploration.
The challenge
The behaviour of the LCS remains difficult to forecast with sufficient accuracy to guide operations beyond a few days, yet its significance for processes and operations in the Gulf of Mexico drives a need to improve and extend forecasts of the LCS and LCEs. The difficulty has arisen partly because interactions of the upper currents with deep eddies have not been detectable in real time to guide numerical models.
Unlocking the Gulf current – a continuance
Sonardyne were introduced to this challenge back in 2018 when the University of Rhode Island launched a multi-year scientific study that included deployment of five Sonardyne Current Pressure Inverted Echo Sounders (CPIES) at depths down to 3,500 m in the area of the extended LCS.
The Sonardyne solution
Sonardyne’s modem-enabled CPIES were a key element in the initial two-year project. These instruments were part of a mass deployment to measure two-way travel time (or tau) over an extended area in order to map the local horizontal velocity and density fields in the extended LCS, as can be read at https://www.sonardyne.com/case-study/unlocking-the-gulf-loop-current/.
Soon after the 2018 deployment, Sonardyne began the development of Origin 65, a combined PIES and ADCP with acoustic modem to enable adaptive data harvesting. The benefit of Origin 65 over CPIES is that it not only supports but augments density/current mapping projects.
Where CPIES use a separate single point current meter to provide a deep reference velocity for calculated geostrophic currents, Origin 65 measures a whole profile of currents over a greater range. Being an all-in-one instrument, Origin 65 also removes the risk and expense of combining separate devices for a single application.
What’s more, by utilising Origin 65’s onboard Edge data processing capability, PIES data is time-synchronised and fused with the ADCP measurements for simpler analysis. After extensive trials, Origin 65 was launched in 2023.
“Pulses of strong currents pose a hazard to industry along steep escarpments in the deep Gulf. Moreover, their unexpected arrival compounds the hazard: satellite and near-surface observations and numerical models do not predict them reliably. We needed a forecast tool grounded in observations with adaptive reporting capability. We had a tall order for the observations: We needed to profile currents from the bottom through hundreds of meters above the bottom and we required fast acoustic telemetry capability. Sonardyne committed the engineering capability to develop a combined PIES and upward-looking low frequency ADCP with a vertical range of 800 m. It was an outstanding match to our needs, and Sonardyne’s fast acoustic telemetry capability was key to being able to harvest the data and report it ashore in near-real time.”
Professor D. Randolph (Randy) Watts, Professor of Oceanography, University of Rhode Island
The 2024 deployment
In 2024, funded by the US National Academies of Science, Engineering, and Medicine Gulf Research Programme and led by a team of scientists from the University of Rhode Island, five Sonardyne Origin 65 units were deployed alongside the original Sonardyne CPIES in the Gulf of Mexico (depth range of 1,800 – 3,200 m) for an initial 18-month measurement campaign.
Both the Origin 65s and CPIES have integrated acoustic modems enabling high-speed (up to 9,000 bps) acoustic telemetry to support wireless retrieval of data by an uncrewed surface vessel (USV) in addition to remote control of the instruments.
Despite similar telemetry capability, the volume of data generated by Origin 65 compared to CPIES is much greater, and therefore limited acoustic bandwidth presents a challenge when looking to transfer this substantial data via acoustic telemetry.
This is where Origin 65’s Edge onboard data processing capability comes into play to condense the bulky raw data into small packets of actionable information, easily exportable via the acoustic modem.
The five Origin 65 units were deployed with an Edge application (app) installed to perform combined onboard processing of the ADCP and PIES data. More specifically, the Edge app implemented a custom algorithm that produced an hourly compact (24 bytes) binary output containing a timestamp, the mean current speed and bearing in six depth-bins above the bottom, plus the mean of the PIES results.
The beauty of the onboard data processing was apparent during planned USV visits, where it took less than 20 minutes to acoustically harvest more than two months’ worth of data
An assessment was conducted whereby the integrated acoustic release on one of the Origin 65 instruments was triggered after 66 days of deployment to allow recovery (Figure 1) of the device and complete data download for a thorough evaluation. This instrument was located in a water depth of 2,142 m.

Figure 1: Retrieval of the Origin 65 aboard the R/V Pelican.
Pies
The PIES portion of the Origin 65 performed consistently (Figure 2). Periods of increased scatter in the sound speed measurements are observable, but these are a result of higher ambient noise levels (pretrigger RMS), which correspond to higher sea states (local wave activity is a dominant source of acoustic noise given that in higher sea states the surface return from the PIES chirp is more spread out).

Figure 2: PIES sound speed and ambient noise (pretrigger RMS) measurements for the deployment. The bottom plot compares ambient noise (pretrigger RMS) to the level of local wave activity using wind speed (as recorded by station Green Canyon 338, 124 km to the WNW of the deployment site) as a proxy for sea state.
ADCP
Velocity data demonstrates expected current behaviour (Figure 3), with velocities much larger in the Eastward and Northward directions than in the upward direction. The lack of significant apparent velocity in the vertical direction indicates that there is no systematic bias in the beam-frame Doppler velocities.
In addition, the observed velocity signals (large blue and red patches) vary on timescales between days and weeks, which is expected.
Of particular interest, it can be seen around 6th June, the prevailing current changed from South-Easterly to North-Westerly over the course of around two days.
This corresponded with a sudden increase in scatter density, thought to be an indication that the seabed was disturbed by the changing current.

Figure 3: Components of the Earth-frame velocities for the 66-day deployment (60-ping ensembles).
Low scatterer concentration in the deep waters (>2000 m) of the Gulf of Mexico reduced the effective profiling range of the Origin 65 from its achieved maximum range of > 800 m. However, with a sufficiently long averaging period it can been seen that the current velocity signal is present for the entire 800 m range of the Origin 65 (Figure 4).

Figure 4: Comparison of 24-hour averages of Eastward current velocity for different altitude bins. Performing increased averaging shows that a consistent current velocity signal is exhibited across the 800 m range of Origin 65.
“Our collaboration with the University of Rhode Island has been instrumental in augmenting our PIES technology in the form of Origin 65, a combined ADCP and PIES, for oceanographic study of geostrophic currents fields like that found in the Gulf of Mexico. We’re delighted to see Origin 65 being applied in this vital study, and by extension, to be able to support research efforts to improve and extend forecasting of the LCS and LCE behaviour with the accuracy desired. We look forward to continuing our relationship with the University of Rhode Island, and to seeing further successful USV data harvests from the Origin 65 units over their deployment period in the Gulf of Mexico.”
Michelle Barnett, Business Development Manager – Ocean Science, Sonardyne
What’s more, evidence of diel plankton migration is apparent with the repeated appearance and disappearance of a scattering layer between 500 m and 800 m height above the bottom. This pattern has a period of roughly 24 hours with the scattering layer clearly visible in daylight hours, as is consistent with the cycle of diel vertical migration observed ubiquitously in aquatic systems throughout the world.
This is nicely demonstrated in cross-correlation data, where values increased to around 80% on a daily cycle in response to the plankton migration (Figure 5). This cross-correlation data helps to indicate the effective maximum range of the system of around 800 m.

Figure 5: An excerpt (4 – 7th June) of unaveraged cross-correlation data for each of the four beams of the Origin 65 demonstrating a clearly observable diel vertical migration pattern. The lower plot represents the local time, with the colour being a function of the local solar altitude.
“This suite of instrumentation and platforms will help refine predictive tools for future applications in the Gulf. Looking ahead, the combination of Sonardyne Origin 65 current profilers and adaptive data-harvesting technology opens the door for long-term deployments in deep water – anywhere in the world. This is very exciting: we could access remote and critically important regions supporting sustained observations and advancing science.”
Professor Kathleen (Kathy) Donohue, Professor of Oceanography, University of Rhode Island
What’s next?
Two successful data harvests by a SeaTrac SP-48 USV equipped with a Sonardyne HPT 7000 L transceiver head have already been conducted. A third data harvest is scheduled for the end of July and the instruments will be recovered in September 2025. Keep an eye on our website and social media for further information about this and the data captured.
If you have an operational challenge for Origin 65, or any other Sonardyne product, please contact us.
Overview
When it comes to USBL and LUSBL transceivers, one model does not fit all situations and vessels. For Ranger 2 and Marksman installations, our High Performance Transceiver (HPT) is available two primary configurations.
HPT 5000
HPT 5000 offers full hemispherical acoustic coverage so it’s a popular choice for tracking multiple targets  (ROVs, AUVs, towfish, seafloor sensors) over a wide range of depths and elevations. The unit is also suitable for dynamic positioning reference on survey, research and offshore support vessels.
HPT 7000
HPT 7000 is engineered for ultra-deepwater operations, tracking targets far below (rather than to the side) of a vessel, and also high vessel noise operating environments, as those typically encountered on DP drilling and construction where aeration from thrusters is liable to cause signal interference.
Both models of transceiver fully support 6G LBL operations using Fusion 2 LBL software. They are also highly capable acoustic communications modems, able to interrogate, command and recover data payloads from deployed Sonardyne instruments including AMTs and Fetch. Supporting telemetry rates of up to 9,000 bps minimises the time a vessel has to wait on location to recover data, as well as supporting LBL operations.
HPT 5000/7000s are also available in Gyro USBL configurations offering calibration-free installation and use.
At a glance
- Use with Ranger 2 USBL and Marksman LUSBL systems
 - Can also be used to communicate and harvest data from Sonardyne sensors
 - Hemispherical (HPT 5000) or directional (HPT 7000) arrays to suit your vessel and application
 - Can be deployed other-the-side, through-tube or through-hull
 - Suitable for new-build vessels or USBL/LUBL upgrade for your existing vessel
 
All HPTs are built on our 6G technology platform with multi-element processing to enable transponders to be positioned more precisely, more quickly and more robustly due to improvements in signal processing algorithms and array design.
Functionality such as ‘Discovery Mode’ enables vessels equipped with Ranger 2 and Marksman to enter an offshore area and automatically detect previously deployed transponders (including their configured address and channel), making simultaneous operations using shared seabed arrays possible.
Manufactured in aluminium-bronze, HPTs are intended to be fitted temporarily or permanently to a vessel’s through-hull or over-the-side pole. HPT 5000s (including Gyro USBL 5000s) have also been fitted to large USVs for uncrewed missions controlled from over-the-horizon.
For specialist applications, inverted USBL, LMF frequency and extreme depth range HPT transceivers are also available. Please get in contact to discuss your requirements.
Ranger 2 in action
Optimising shallow water positioning for combined magnetometer and hydrographic surveys
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Read moreSpecifications table
level, vessel noise, water depth, mechanical rigidity of the transceiver deployment machine, SV knowledge and proper calibration of
the total system using CASIUS.
| Feature | Type 8142-001 | Type 8142-002 (deepwater optimised unit) | |
|---|---|---|---|
| Operational frequency | MF (20–34 kHz) | MF (20–34 kHz) | |
| Transceiver performance  | 
Operating range | Up to 7,000 m | Up to 7,000 m | 
| Acoustic coverage | Up to ± 90° | Up to ± 90º Optimised for deep water (depending on frequency of operation)  | 
|
| Range precision | Better than 15 mm | Better than 15 mm | |
| Positioning repeatability | All transceivers tested to better than 0.1% of slant range 1 Drms | All transceivers tested to better than 0.07% of slant range 1 Drms | |
| Transmit source level (dB re 1 µPa @ 1 m) | 200 dB | 200 dB | |
| Tone Equivalent Energy (TEE) | 206 dB (13 JA) | 206 dB (13 JA) | |
| Electrical | 48 V dc (±10%), Typical 15 W, Max 120 W  | 
48 V dc (±10%), Typical 15 W, Max 120 W  | 
|
| Communication | RS485, baud rate switchable, ethernet 100 Mbps  | 
RS485, baud rate switchable, ethernet 100 Mbps  | 
|
| Operating temperature | -5 to 40°C | -5 to 40°C | |
| Storage temperature | -20 to 45°C | -20 to 45°C | |
| Mechanical construction | Aluminium bronze | Aluminium bronze | |
| Dimensions (length x diameter) | 322 x 225 mm | 391 x 310 mm | |
| Weight in air/water | 26.7/15.3 kg | 46.9/29.0 kg | |
| Options | Tilted array adaptor | Tilted array adaptor | 
Frequently asked questions
How to clean a transceiver array face
How to enter Transceiver & Lodestar Offsets for Optimised USBL
HPT Deployment Tests
Has anyone ever installed an echosounder and Ranger 2 USBL transceiver directly beside each other? Would this work?
How do USBLs work?
Does the HPT’s main connector need any maintenance?
When to use Depth Aiding
What acoustic address should I use for my USBL transponder
How to interface Ranger 2 into a 3rd party survey system
STP files
Software and firmware
Software and control hardware
Datasheets
Did you know?
Both HPT 5000 and 7000 are available in Gyro USBL configurations
Overview
Acoustic release transponders are a vital piece of ocean equipment – relied upon by energy, defence and science users to moor valuable equipment strings for years at a time, and when commanded to do so, reliably return equipment and logged data to the surface.
Transponders need to be tough, reliable and easy to work with. RT 6-6000 meets these requirements.
Part of our new range of acoustic releases, RT 6-6000 combines the extensive mechanical design track record of our renowned ORTs and DORTs with the flexibility of our 6G platform, resulting in enhanced battery life and perhaps most significantly, compatibility with our Ranger 2 USBL family
With RT 6-6000, you can use your vessel’s Ranger 2 USBL to deploy, track, locate and command the instrument – removing the need for a separate topside unit. If you don’t have access to a Ranger 2 USBL, our rugged and lightweight Deck Topside with an over-the-side dunker is all you need to both configure and command RT 6-6000s.
At a glance
- Tested, loaded, deployed and released using Deck Topside
 - Also works with Sonardyne Ranger 2 USBL to deploy, track and command in very deep water
 - Highly reliable release mechanism design and thousands are in service globally
 - Working Load Limit 1,275 kg (4:1)
 - Depth rated to 6,000 m
 - External battery disconnect to maximise battery life with no need to open unit
 - Compact and rugged design
 
RT 6-6000s are most commonly used to anchor oceanographic moorings to the seabed. However, their compact size and compatibility with Ranger 2 makes them ideal for incorporation into instrument frames or lowered platforms to enable deployment of sub-system packages.
Standard features include a Working Load Limit of 1,275 kg (at 4:1) and a spring-assisted release mechanism. RT 6-6000 is compatible with our standard tandem and high-load release frames for scenarios requiring a higher WLL. Speak to us about your requirements as custom frames are also an option.
A battery disconnect fob is located on the transducer and uses an internal magnetic switch to electronically disconnect the battery when not in use. This means you do not have to open the unit to manually disconnect the battery, saving time and reducing the risk of incorrect re-assembly.
RT 6-6000s use the same trusted spring-assisted release mechanism that has been in service for many years and used on thousands of Sonardyne transponders globally.
Choice of topsides
You can use our rugged Deck Topside, or if you’ve got access to a Ranger 2 USBL system on your survey or research vessel, then you have everything you need to control your RT 6-6000.
Versatile
RT 6-6000 is more than just an acoustic release. It can be tracked with our Ranger 2 USBL making relocating and recovering it fast and simple.
High WLL
Use it with our Heavy-Duty Release Frames and significantly increase your Working Load Limit when deploying seabed structures.
Support
You can find a wide range of support articles for our family of acoustic release transponders on our knowledge base.
Specifications table
| Feature | Type 8321-6250 | 
|---|---|
| Depth Rating | 6,000 m | 
| Operating Frequency | LMF (14–19 kHz) | 
| Transducer Beam Shape | Hemispherical | 
| Transmit Source Level (dB re 1 µPa @ 1 m) | 188 dB | 
| Tone Equivalent Energy (TEE) | 192 dB | 
| Receive Threshold (dB re 1 µPa) | <90 dB | 
| Working Load Limit (4:1) | 1,275 kg | 
| Proof Load | 2,550 kg | 
| Breaking Load | 5,100 kg | 
| Maximum Safe Release Load | 1,700 kg | 
| Battery Life (Alkaline) | >32 months | 
| Inclinometer Accuracy | ±5° | 
| Surface Unit | Deck Topside, Ranger 2 USBL | 
| Mechanical Construction | Aluminium bronze and duplex stainless steel | 
| Operating Temperature | -5 to 40°C | 
| Storage Temperature | -20 to 55°C | 
| Dimensions (Length x Diameter | 700 x 142 mm (27.5 x 5.6”) | 
| Weight in Air/Water | 20/15 kg | 
| Standards | CE Marked to EN-60945, EN-61010 | 
| Options | Deep Water Deck Kit (Deck Topside) – 602-0180 | 
| Heavy Duty Release Frames (7.5 T, 15 T and 25 T) | 
Frequently asked questions
What is an Acoustic Release and how does it work?
Why isn’t serial communication available using the iWand in RT 6 Dunker Mode?
6G Terminal Lite Range Test
What is the safe working load for different RT 6 products?
What should I use instead of an ORT and DORT?
How to correctly set an RT 6-6000 release mechanism
How to change the battery on an RT 6-3000 or RT 6000
How to load the release on an RT 6-3000 and RT 6-6000
Which RT 6 is correct for my operations?
How to release an RT 6 acoustic release transponder using Ranger 2
How long can an RT 6-3000 and RT-6 6000 be deployed for?
Deployment
STP files
Software and control hardware
Manuals and quick start guides
Did you know?
RT 6-6000 can be used with our Ranger 2 USBL family or Deck Topside
Overview
Gyro iUSBL combines our generation high performance HPT Inverted USBL transceiver and a Lodestar Attitude and Heading Reference System (AHRS)/Inertial Navigation System (INS) in the same titanium pressure rated mechanical assembly capable of operating at depths of 7000 m.
With the AHRS/INS in fixed mechanical alignment to the iUSBL’s pressure balanced acoustic array, the Gyro iUSBL can be quickly deployed without need for a calibration to determine the alignment of the ship’s motion sensors to the acoustic transceiver. For many applications, this can enable significant time savings and operational costs.
At a glance
- Designed to work with Ranger 2 USBL
 - Tracks your deep tow vehicle beyond 10,000 m
 - Integrated USBL transceiver and SPRINT INS
 - Depth rated to 7,000 m
 - Offers 10x improvement in positioning precision
 
Specifications table
| Features | Type 8084-000-7535 | |
|---|---|---|
| Operational Frequency | MF (20–34 kHz) | |
| Transceiver Performance  | 
Operating Range | Up to 7,000 m | 
| Pressure Rating | Up to 7,000 m | |
| Acoustic Coverage | Up to ± 90° | |
| Range Accuracy Positioning Repeatability | Better than 15 mm All transceivers tested to Better Than 0.1% of Slant Range 1 drms  | 
|
| Transmit Source Level (dB re 1 µPa @ 1 m) | 200 dB | |
| Tone Equivalent Energy (TEE) | 206 dB | |
| Heading | Range | 0–360° | 
| Accuracy | 0.05 to 0.1° secant latitude | |
| Settle Time | <5 minutes | |
| Follow Up Speed | 500° / second | |
| Resolution | 0.01° | |
| Pitch & Roll | Range | ±180º (No physical limit) | 
| Accuracy | 0.01° | |
| Resolution | 0.01° | |
| Heave | Range | ±99 m | 
| Accuracy (Real Time) | 5 cm or 5% (whichever the greater) | |
| Resolution | 0.01 m | |
| Electrical | +48 V dc maximum 160 W | |
| Communication | RS485, baud rate switchable, ethernet 100 Mbps | |
| Operating Temperature | -5 to 40°C | |
| Storage Temperature | -20 to 55°C | |
| Dimensions (Length x Diameter) | 475.5 mm x 240 mm (without end connector) | |
| Weight in Air/Water | 45/24 kg | 
Frequently asked questions
Software and firmware
Datasheets
Manuals and quick start guides
Did you know?
Gyro iUSBL is depth rated up to 7,000 m
Reassuringly reliable Ranger 2
Ranger 2 is more than just an acoustic tracking and positioning system. It goes way beyond tracking; it can be part of a dynamic positioning system, it supports robust two-way data communication with a range of seafloor sensors to collect data, it can support AUV command and control and will even release seabed moorings.
Ranger 2 can even be run from an uncrewed surface vehicle (USV) enabling truly remote, autonomous operations. Whether your mission involves seabed surveys, offshore energy site inspections or commanding a fleet of AUVs, Ranger 2 can help you expand them over the horizon and to the edges of your imagination.
It comes with an impressive list of standard features, our award-winning 6G (sixth generation) acoustic hardware platform and Sonardyne Wideband 2 digital signal architecture. The flexibility of the Ranger 2 family is further extended by our range of 6G transponders to support a wide variety of applications.
Why should you invest?
Our Ranger 2 family gives you the versatility you need, at the investment level you can afford, to get your project completed quickly and efficiently. It’s engineered like no other USBL on the market. Adaptable, scalable and always compact, there is a Ranger 2 USBL to suit any size vessel or project. As your needs grow, bolt-on software packs unlock additional capability and protect your investment. Whichever size suits you best, they will always be compatible with our full range of 6G transponders and many other vessel systems.
                Micro-Ranger 2 USBL
The ‘baby’ of the Ranger 2 family and the ideal entry-level USBL, Micro-Ranger 2’s compact size contradicts its impressive performance. It may be our smallest underwater tracking system to date, but it will have a big impact on your operations.
Never used a USBL system before? No problem. Micro-Ranger 2 is simple to setup and use.
Need to know where your targets are? Micro-Ranger 2 has them covered. Precision, ease of use and versatility come as standard. It’s built around the same market-leading hardware and digital acoustic technology you’ll find in our family of deep water USBL systems, but for significantly less cost and complexity.
For the full picture of what your Micro-Ranger 2 USBL is capable of, please visit its dedicated product page.
                Mini-Ranger 2 USBL
Mini-Ranger 2 is our mid-level USBL target tracking system, perfect for nearshore operations; UXO surveys, search and recovery and structure inspections. With a 995 m operating range, extendable to 4,000 m, it can track up to ten underwater targets simultaneously, including divers, towed instruments, ROVs and AUVs.
Choose to add the Marine Robotics software pack and it will communicate with subsea robotic platforms, sharing positions and exchanging data.
A compact, easily installed, system it’s your ideal choice for temporary installation on small survey vessels, as well as USVs.
For the full picture of what your Mini-Ranger 2 USBL is capable of, please visit its dedicated product page.
                Ranger 2 USBL
Ranger 2 is the largest USBL in the family and the most powerful USBL on the market. Able to simultaneously track up to 99 targets with up to 11,000 m range, it is anything but standard.
Recommended for installation on large vessels and USVs, Ranger 2 incorporates over 30 years of our USBL innovation and know-how. It has a global vessel track record and is used for offshore energy, research, cable-lay, salvage and naval operations, to name but a few.
Sharing a common platform with other Sonardyne USBLs, Ranger 2 supports all industry standard DP telegrams and acoustically aided inertial navigation systems (INS).
For the full picture of what your Ranger 2 USBL is capable of, please visit its dedicated product page.
6G
Our 6th generation (6G) technology provides faster, secure and robust data communications from seabed to surface . This gives you speedier updates on the location of your assets and access to your vital data.
Wideband
Our wideband technology enables digital high-throughput data, range resolution and accuracy with low latency. Teamed with our 6G it gives you fast, reliable, accurate data over greater distances.
Robotics
Uncrewed, autonomous surface and underwater vehicles are increasingly used for coastal, deep sea and over-the-horizon operations, reducing costs, risks and carbon footprint. Thats why we have a dedicated “bolt on” pack for our Ranger 2 to enhance your robotics operations.
Dynamic positioning
We’ve been engineering high integrity position reference systems for dynamically positioned vessels since the early 1990s. Our USBL, LUSBL and SPRINT- INS products provide dynamic positioning solutions for a range of vessels and environments.