Combines high altitude and high resolution with 400 kHz and 600 kHz versions
Adaptive bottom lock provides reliable navigation over different seabed types
Easy to install; same hole mounting pattern as many 3rd party DVLs
4,000 m, 6,000 m and OEM versions

Fly higher. Navigate deeper. Profile in a single ping

Use Syrinx as a standalone DVL or ADCP, as part of an integrated navigation system, or perform all these functions at once. Built in the UK for easy export, it maintains bottom lock at up to 230 m altitude, supports dual outputs, has replaceable transducers and comes in a 4,000 m (400 kHz and 600 kHz), 6,000 m (600 kHz) or OEM housing. How does your current DVL compare?

Syrinx is a class leading Doppler velocity log (DVL) for surface and subsea vehicles, available in two frequencies; 600 kHz or 400 kHz for higher altitude tracking up to 230 m. The Syrinx variants combine high resolution and high altitude tracking, in single, easy to install navigation instruments. The adaptive bottom lock technology inside Syrinx provides consistency and reliability over challenging and changing topography and works at an altitude higher than 85% of the world’s subsea infrastructure. This reduces the amount of time a vehicle has to dive on free inertial. If water profiling is a mission requirement, Syrinx’s highly capable ADCP mode enables navigation and profiling without the need for separate instrument, saving you cost and payload.

When tightly integrated with Sonardyne’s INS, SPRINT, unmatched DVL-aided navigation can be achieved. This allows for enhanced performance through optimisation of beam-level data passed between Syrinx and SPRINT to aid velocity prediction and outlier rejection, with positioning able to continue even if one or two DVL beams are unavailable.

For the ultimate integration Syrinx and SPRINT are also available as a single combined unit with integral pressure sensor. SPRINT-Nav is one of the smallest inertial DVL instruments available on the market suitable for almost any ROV and survey task.
Syrinx runs an embedded System Manager using a web browser, eliminating the need to install dedicated PC software. This allows configuration and testing of Syrinx prior to deployment, control of Syrinx during subsea operations, and visualisation of the navigation data.

The hardware and vehicle interfacing has been designed to be easy to install, set up and use and is compatible with DVL/ADCP mounting arrangements from other vendors. With similar dimensions to existing DVLs and ADCPs, there should be no need for modifications to subsea vehicles in order to upgrade to Syrinx. PD0, PD3, PD4, PD6, PD13 telegrams are supported for integration to third party navigation systems.

A 4,000 m rated titanium housing is supplied as standard to meet the requirements of Work-class ROVs. 6,000 m and OEM (no housing) versions are also available. Syrinx’s transducers have been designed, built and tested in-house to provide maximum performance, and can be individually replaced, reducing ownership costs and repair time. The entire array is water blocked meaning that should damage occur to the transducer array, the unit’s electronics are isolated from water ingress.
Syrinx is designed and manufactured entirely in the UK. This means it can be exported to countries within the European Union and selected others (including the USA) without the need for a specific export licence.

Why Syrinx?


  • 400 or 600 kHz frequency
  • 4-beam array @ 30 degree angles
  • Up to 25 kHz DVL ping rate
  • Up to 4 Hz ADCP ping rate


  • 4,000 m and 6,000 m depth rated options
  • Max 204 mm x 225 mm, 8.2 kg weight in water (6,000 m version)
  • Titanium housing as standard; OEM option
  • Replaceable transducers; water block array
  • Onboard web UI for setup and configuration


  • 0.4 /230 m min/max altitude
  • 0.4–120 m ADCP profile range
  • >10 m/s velocity range (DVL)
  • 0.01 cm/s velocity resolution (DVL)
  • Up to ±11.2 m/s ±0.4% of measured value (ADCP along-beam)


  • What’s in the box: Syrinx DVL/ADCP and QuickStart guide
  • Warranty: 1 year return to Sonardyne service centre
  • ITAR Controlled: No
  • UK Export License: Not required

More about this product

Syrinx - Doppler Velocity Log Specifications & DataSheet

Feature Type 8275-4531/6531 600 kHz Type 8275-4561  400 kHz
Operational Frequency 600 kHz 400 kHz
Bottom Velocity – Single Ping Precision Standard Deviation @ 1 m/s* ±0.22 cm/s ±0.28 cm/s
Long Term Accuracy ±0.12% ±0.1 cm/s ±0.22% ±0.1 cm/s
Minimum/Maximum Altitude 0.4/175 m** 0.4/230 m
Velocity Range 10 m/s 10 m/s
Velocity Resolution 0.01 cm/s 0.01 cm/s
Data Output Rate 25 Hz max 25 Hz max
Water Reference Velocity Accuracy
Layer Size
Minimum/Maximum Range
±0.2% ±0.1 cm/s
0.4 m/80 m
±0.2% ±0.1 cm/s
0.4 m/120 m
ADCP Profiling Range
Velocity Range & RMS
(along beam)
Maximum Number of Cells
Maximum Ping Rate
0.4–80 m
Up to ±11.2 m/s ±0.4%
of measured value
4 Hz (ADCP) or 2.5 Hz (DVL+ADCP)
0.4–120 m
Up to ±11.2 m/s ±0.4%
of measured value
4 Hz (ADCP) or 2.5 Hz (DVL+ADCP)
Acoustics Beam Width
Beam Angle
Maximum Transmit Source Level (dB re 1 uPa @ 1 m)
±1.0 Degrees
30 Degrees
217 dB
±1.3 Degrees
30 Degrees
217 dB
Sensors Temperature
Pitch/Roll (Optional)
Pressure (Optional)
-5° to 40°C/s
±0.1% full scale
Configuration Array 4-beam array @ 30° beam angles
Communication and Logging Communications

Trigger Inputs
Internal Logging

Dual RS232, multi-port Ethernet
(TCP and UDP)
3 V–12 V rising or falling edge configurable
32 GB internal memory
Output Output Telegrams Sonardyne proprietary, PD0, PD3, PD4, PD6, PD13, SDDBT Simultaneous telegram output
Power Voltage Range (DC Input)
Average Power (Typical)
24 V (±10%)
10 W nominal
Environmental Depth Rating
Operating Temperature
Storage Temperature
4000 m/6000 m
-5 to 55°C
-20 to 55°C
Mechanical  Construction Titanium 
Connector Type Subconn
Dimensions (Height x Max Diameter) 189 x 225 mm (4,000 version)
204 x 225 mm (6,000 version)
189 x 225 mm (4,000 version)
Weight in Air/Water*** 12.1/7.6 kg 4,000 m version)
14.7/8.2 kg (6,000 m version)
11.5/6.7 kg (4,000 m version)

*Standard deviation refers to proven single-ping true horizontal velocity precision, specified at 20–30 m altitude.
**150 m bottom acquire range, up to 175 m once bottom locked in optimal seabed conditions.
***Estimated weights.


To request a manual simply tick the box next to the manual you require and then press the Request Form button. You will then be able to request addition manuals for other products and your request will be emailed to our Customer Support Team who will reply to your enquiry. Alternatively please contact your local office who will be more than happy to help.

User Manual - Syrinx DVL
QSG - Syrinx DVL Operation Quide

  • Manuals Request


    Instrument Firmware Description
    Syrinx DVL Firmware

    Release 2 Revision C


    Technical BULLETINS

    Title Description
    Syrinx DVL Firmware Release 2 Revision C
    No: TB17-005
    This version of firmware improves system timing stability and logging functionality which may cause some messages to have a delayed response. This would have been evident by a trigger going into the unit but a delayed reply being output rather than immediately after the acquisition processing has completed.


    What are the maximum and minimum altitudes that Syrinx DVL will operate?

    The maximum operating altitude is up to 140 m, depending on seabed composition, acoustic noise and sedimentation in the water column.

    The minimum operating altitude is 0.5 m. Below this altitude the velocity errors begin to grow very large but velocity estimates can still be made to around 0.3 m. 

    Mounting the DVL as high as possible on the vehicle while maintaining line of the sight for all 4 beams allows for the best results in very low altitude scenarios.


    What are the maximum and minimum velocities that Syrinx can detect?

    Minimum velocity measurements are <1mm/s in X, Y and Z (or beam) velocities when using the Sonardyne proprietary telegram. This increases to 1 mm/s when using PD4/PD5 telegrams.

    Maximum velocity measurement capability is 10 m/s.


    What is the maximum rate that I can ping?

    10 Hz or 10 pings per second, water depth allowing. In deeper water, ping rates may be reduced due to allow for acoustic propagation time.


    Can I externally trigger Syrinx?

    Yes. Syrinx can be triggered from a rising or falling edge. This can be configured either through the configuration software or via command line. The trigger needs to be 3-12 V and able to drive at least 5 mA.


    How do I correct for speed of sound?

    A command can be used to set the speed of sound within the DVL, which will then scale all measurements using this value. It is also possible for the DVL to output measurements using a fixed SV value, and the measurements can later be scaled in external navigation software.


    What is the maximum seabed slope that I can still bottom track?

    The maximum seabed slope on which bottom lock can be attained is highly dependent upon a number of different factors. Some examples include height difference between ranges (amplified difference if slope is steep and altitude on some beams is very low and others are high) and also backscatter properties based on incidence angle of the acoustic pulse on the sea floor. 

    An example statistic would be that at 10 m altitude, Syrinx will be able to track steep slopes of up to 75°. At very shallow altitude (1-2 m) the DVL would be able to track on a slope of 45°.


    What interference might I get between Syrinx and the other acoustic equipment on my vehicle?

    Acoustic interference will vary depending on the equipment that is fitted on the vehicle.  Acoustic transmissions of similar frequencies can cause interference with the DVL operation. The best way to manage interference is to time pulses from interfering devices either synchronously or asynchronously. From experience it is recommended to trigger asynchronously to prevent devices from acoustically interfering with one another.

    How do I mate and calibrate a SPRINT or Lodestar to my DVL?

    An optional co-locating plate (part number 650-0156) allows a DVL and SPRINT/Lodestar to be mated and pre-calibrated prior to mobilising offshore. If needed, the same calibrated DVL and SPRINT/Lodestar can be uncoupled, used independently and then re-connected and still be considered calibrated such is the precision of the Sonardyne co-locating arrangement.


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