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RT 6-6000

Acoustic release transponder

Engineered for: Seabed, Structure

Release Transponder 6 (RT 6-6000) is a tough, reliable oceanographic release transponder designed for a deep water applications with energy, defence and science

At a glance

Use it with your Sonardyne Ranger 2 USBL to deploy, track and command in very deep water

Highly reliable release mechanism design; thousands in service globally

Working Load Limit 1,275 kg (4:1)

Depth rated to 6,000 m

External battery disconnect to maximise battery life; no need to open unit

Compact and rugged design

Deploy, track, moor and recover your equipment

Want to know more?

Benefits of RT 6-6000 for your operations

USBL topside

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.


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.


Acoustic release transponders are a vital pieces 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 system.

With RT 6-6000 you can for the first time use your vessel’s Ranger 2 USBL to deploy, track, locate and command the instrument – removing the need for a separate topside unit.

For users without access to a Ranger 2 USBL, a portable dunker unit is available to command RT 6-6000s.

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.

On the back deck prior to deployment, RT 6-6000 is configured with our iWand hand-held acoustic transponder test and configuration device.

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.



Feature Type 8321-6415
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 active
Inclinometer Accuracy ±5°
Surface Unit Sonardyne 6G transceiver
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
Options Parallel Release Kit
Heavy Duty Release Frame
Standards CE Marked to EN-60945, EN-61010

Manuals and quick start guides

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Deploy, track, moor and recover your equipment