Bathymetry
Sounder S500 Single-Beam Echosounder
Sounder S500 - transducer, control board and cables (penetrator shown is not included)
The Sounder S500 is a single-beam echosounder for small ROVs, AUVs and USVs, where size, weight and power are the binding constraints. It runs at 500 kHz with CHIRP modulation, giving about a 5° beam and range resolution down to 3 mm.
A transducer in the water, a board inside your housing
Every figure on this page lives somewhere in the kit. Hover or tap a number to trace it to the hardware.
- 01Transducer cable1 m1 shield + 2 signal wires, JST-GH connector fitted.
- 02Transducer54 mm × 22 mm2 × M4×0.7 inserts 28 mm apart. 94 g in air, 50 g in water, rated to 300 m.
- 03Beamabout 5°500 kHz, 2-way conical, CHIRP with 20 kHz bandwidth. Range 0.3 to 100+ m.
- 04Power cable10–30 V2-wire lead with JST-GH, 60 cm. 2.5 W idle, 5 W at maximum ping rate.
- 05Control board69 × 38 mmLives inside your vehicle’s existing pressure housing. 34 g.
- 06InterfacesEthernet 100 Mb/sRJ45. Also USB 12 Mb/s (micro-USB) and 3.3–5.0 V serial 115 kbaud (6-pin JST-GH).
Every Sounder S500 Configuration
Order the full kit unless you are replacing a part of a Sounder you already run.
Penetrator shown is not included
What differs between the configurations▾
| Specification | Full kit - transducer + cabling | Control board (PCB) only | Transducer only (metal) |
|---|---|---|---|
| You get | Control board + transducer + cabling | Control board only | Metal transducer only |
| Buy this if | It is your first S500 | You are replacing part of an S500 you already run | You are replacing part of an S500 you already run |
Everything else on this page is common to all 3 configurations; which vehicle each one is cut for is on the cards above.
Key specifications14 rows▾
| Acoustic frequency | 500 kHz |
| Beam width (2-way, conical) | about 5° |
| Modulation | CHIRP with 20 kHz bandwidth; monotone ping also supported |
| Minimum range | 0.3 m |
| Maximum range | 100+ m |
| Range resolution | 3 mm to 17 m · 9 mm to 50 m · 24 mm beyond 50 m |
| Depth rating (transducer) | 300 m |
| Power supply | 10–30 V · 2.5 W idle · 5 W at maximum ping rate |
| Maximum ping rate | 10 pings/sec to about 65 m · about 7 pings/sec at 100 m |
| Interfaces | Ethernet 100 Mb/s (RJ45) · USB 12 Mb/s (micro-USB) · 3.3–5.0 V serial 115 kbaud (6-pin JST-GH) |
| External sync | 3.3–5.0 V digital sync input, to time pings away from other acoustics |
| Dimensions - PCB | 69 × 38 mm · 4 mm below and 18 mm above the mounting surface |
| Dimensions - transducer | 54 mm diameter × 22 mm, 2 × M4×0.7 inserts 28 mm apart |
| Mass | PCB 34 g · transducer 94 g in air, 50 g in water |
Ping rate is bounded by the speed of sound, not by the electronics: a ping cannot be sent until the previous one has travelled to the set range and come back. The 10 pings/sec headline holds to roughly 65 m. This is true of every echosounder ever built. Cerulean also note that CHIRP itself can reduce the rate in some circumstances, because of the computational overhead of the correlation.
Sync input is available. Cerulean list the 3.3 V sync OUTPUT as pending a firmware update - ask us for the current status before you design around it.
Range resolution is banded, and the bands matter: 3 mm holds to 17 m, not beyond. Reduced resolution is available as an option where you want to cut the waterfall data rate.
Published by Cerulean - specification page. The maximum ping rate figures are published by Cerulean - SonarView device controls
Applications▾
- Altimeter for an ROV or AUV - altitude above the seabed, with bottom tracking running on the device itself
- Bathymetry from a USV, where the depth data is geo-referenced by the vessel’s GNSS
- Obstacle avoidance on an autonomous vehicle
- General underwater distance measurement - tank gauging, structure clearance, anything where you need a range in water
What's in the box▾
Cerulean’s own packing list for this product.
What’s in the box
- 1 × S500 control board
- 1 × transducer with 1 m cable (1 shield + 2 signal wires), JST-GH connector fitted
- 1 × 2-wire power cable with JST-GH connector fitted, 60 cm
- 1 × spare 3-conductor JST-GH connector (GHR-03V-S)
- 1 × oil-resistant Buna O-ring (McMaster-Carr 9452K94)
Not in the box, and needed by most installations: an M10 cable penetrator for 6 mm cable, and a bracket to suit your vehicle. We supply both - see Before you order, below.
Downloads▾
What a 5° beam is for
An echosounder insonifies a cone and reports the distance to the strongest echo inside it. The width of that cone decides whether you get a measurement or an average.
At 10 m altitude, the S500’s 5° beam covers 0.87 m of seabed. A 25° beam - the width used by most bolt-on echosounders in this class - covers 4.43 m at the same altitude. At 30 m the figures are 2.62 m and 13.3 m.
| Altitude | S500 footprint (5°) | Typical wide beam (25°) |
|---|---|---|
| 10 m | 0.87 m | 4.43 m |
| 30 m | 2.62 m | 13.3 m |
| 50 m | 4.37 m | 22.2 m |
| 100 m | 8.73 m | 44.3 m |
Calculated from published beam widths: footprint = 2 × altitude × tan(beam ÷ 2). These are our own arithmetic from Cerulean’s published 5°, not a manufacturer specification. The ratio is constant - 5.1× in diameter, about 26× in insonified area, at every altitude.
That is the case for the S500 and it is also the case against it. A narrow beam resolves features a wide beam averages away. A narrow beam is also less forgiving on a vehicle that pitches and rolls hard, because there is less cone to keep the bottom inside. If the job is obstacle avoidance on a lively platform rather than depth measurement, a wider beam is the better tool and we will tell you so.
Read the full comparison: how narrow should an echosounder beam be?Sounder S500, and what it produces
Photographs of the hardware - not renders.
What CHIRP adds, and what the ping rate costs
Instead of transmitting one tone, the S500 sweeps 20 kHz of bandwidth and correlates the return against the transmitted sweep. That localises the echo in time far more sharply than a single tone, improving both signal-to-noise ratio and range resolution.
Range resolution is banded, and the bands matter:
- 3 mm out to 17 m
- 9 mm out to 50 m
- 24 mm beyond 50 m
Reduced resolution is available as an option where you want to cut the waterfall data rate. Monotone pinging is also supported if you want it.
On the ping rate figure
The 10 pings/sec headline holds to roughly 65 m and falls to about 7 pings/sec at 100 m. That is the speed of sound setting the limit, not the electronics - a ping cannot be sent until the last one has come back - and it applies to every echosounder made. What it means in practice is along-track sample spacing:
| Survey speed | at 10 pings/sec | at 7 pings/sec |
|---|---|---|
| 1 knot | 5 cm | 7 cm |
| 2 knots | 10 cm | 15 cm |
| 3 knots | 15 cm | 22 cm |
At 2 knots that is roughly 10 cm between soundings at short range and 15 cm at 100 m, which is ample for most shallow survey work. We publish it because it is the kind of thing you would rather know now.
The ping-rate figures are published by Cerulean on the SonarView device-controls page and appear nowhere in the specification table. The along-track spacings are our own arithmetic from those figures, not a published specification.
Three things that decide whether it suits your build
Check them, or send us the vehicle and we will check them for you before quoting.
1 - You have 10–30 V DC and one free interface
Ethernet, USB or 3.3–5 V serial, your choice. One detail worth knowing: after each power-up the S500 polls all three and the first one to send a valid packet becomes the host, disabling the other two. Bench-test on USB then deploy on Ethernet and you need a power cycle, not just a cable swap. Source
2 - You are prepared to fit a penetrator yourself
This is the one people underestimate. For most installations you need an M10 cable penetrator for 6 mm cable, which is not supplied. Fitting it means prising open the JST-GH connector with a hobby knife, extracting the three wires, passing the cable through the penetrator and re-terminating. The spare connector in the box exists because this occasionally ruins the original.
The alternative is the O-ring route - seat the supplied O-ring in the groove on the back of the transducer and take the cable directly into a waterproof enclosure. Simpler, but it constrains where the transducer can sit.
Neither is difficult. Both are an afternoon with the vehicle open, and that is the honest trade for the low drag and the 50 g wet mass. If you want a sensor that bolts on and works, say so and we will point you at one. Source
3 - SonarView, if you want the waterfall
The S500 reports a plain distance over its API to any host, and bottom tracking runs on the device, so SonarView is optional. It adds the waterfall display, recording and replay, firmware update and IP configuration. Free, and available for Windows, macOS, Linux and as a BlueOS Extension. Source
We supply penetrators, brackets, hubs, cables and spares - see what fits the Sounder S500Software and integration
SonarView is Cerulean’s free viewer, available as a desktop application for Windows, macOS and Linux, and as a BlueOS Extension. It gives you the fishfinder-style waterfall, live recording, replay of saved files, firmware updates and IP configuration. Speed of sound is adjustable, which matters for accuracy between fresh and salt water.
Output is your choice of a plain distance, a full signal profile for fishfinder-style waterfall display, or raw signal-strength data for analysis.
The S500 speaks a binary packet format compatible with the Blue Robotics Ping-Protocol, so existing Ping tooling - Ping Viewer, ping-python - will talk to it. For Ping1/2 compatibility specifically, Cerulean document setting Pinging ON and Full Profile OFF in the Power On Settings dialog.
Default address is 192.168.2.92 on UDP or TCP port 51200, configurable through SonarView device discovery.
Ping-Protocol packet compatibility and the Ping1/2 compatibility mode are documented by Cerulean - communicating with the Sounder S500. There is no turnkey BlueOS or ArduSub driver for the S500 as there is for the Tracker 650; if you need one, tell us what the vehicle runs and we will say what is involved.
A sounder gives you depth, not position - see positioningCommon questions
Answers Cerulean publish, each linked back to the page it came from.
What is the Sounder S500 for?
Four jobs: an altimeter for an ROV or AUV, bathymetry from a USV, obstacle avoidance, and general underwater distance measurement. Bottom tracking runs on the device, so it reports a distance without any host-side processing. Source
How does it compare to a 25° echosounder like the Ping2?
Both reach 100 m and are rated to 300 m depth. The difference is what each one is built for. The S500’s 5° beam resolves a 0.87 m patch of seabed at 10 m altitude where a 25° beam averages 4.43 m, and CHIRP takes range resolution down to 3 mm. In exchange, the Ping2 arrives sealed with a penetrator and bracket fitted and is on the vehicle in an hour. We supply both - the full comparison is in our echosounder beam width guide. Source
Can it really reach past 100 m?
The specification is 100+ m. Cerulean report the S500 displaying 120 m during testing in Lake Superior, which is deep, clear fresh water and a favourable case. Treat 100 m as the number to plan against. Source
Why does CHIRP matter here?
The pulse sweeps 20 kHz rather than sitting on one note, which improves signal-to-noise ratio and sharpens range resolution to 3 mm out to 17 m, 9 mm to 50 m, and 24 mm beyond. Source
Do I have to use SonarView?
No. The S500 reports a plain distance over its API to whatever host you like, and bottom tracking runs on the device itself. SonarView adds the waterfall display, firmware updates and IP configuration, and it is free. Source
Do I need a DVL as well?
Not for altitude hold - the S500 does that on its own. A DVL measures velocity over ground and is what you need for position hold, dead reckoning or waypoint navigation. They answer different questions. Source
Will it work on my vehicle?
It needs 10–30 V, one free interface, a place to mount a 69 × 38 mm board inside the pressure housing, and a way to get a 6 mm cable through the hull. Tell us the vehicle and we will confirm it before quoting. Source
Request a Sounder S500 quote
Tell us the vehicle and the water depth and we will confirm the exact part number - and say so if a different model suits the job better.
Anything you have added to your quote list is carried into this form automatically.