Sonar air boat working fine

Hello sonar boat designers

My new sonar air boat project is nearly finished. The boat is build from an old bait boat. The brains are a pixhawk controller. The motor and prop (12 x 4.5) are rather large but that seems to be a good thing. In the old design there was an 10 x 4.8 slow fly prop and a smaller motor with a power consumption of 3 A for a speed of 3 km/u. With the new prop we have 1.6 A with the same speed :slight_smile: Power source are two parallel 3s 1p 5000 mAh lipo’s. The sonar is a Lowrance Hook4 and is perfect for this job. The boat is designed for mapping an acid lake. That’s why there is no prop in the water and nearly no metal parts. All metal parts are well insulated with plasti dip. More on the project later once it did it’s job and survived (end of July) :wink:

Best regards


That is cool - mapping an acid lake! Boat looks very good. Keep us informed of your progress. We’d love a video :slight_smile:

Thanks, Grant.

Hello Grant, here is a link of one of my first experiments. Still with the APM 2.6 controller.



The boat looks like it goes great! That is awesome. Nice work. Really appreciate the video - thanks. Keep us informed of how the project goes - love to see more.

Thanks, Grant.

the project at Poas is finished and the boat survived :wink: Some impressions:

This is the 300 m wide lake. The water temperature was 55 C and pH was 0.5. There were a lot of phreatic explosions in the middle of the lake. The yellow rafters are sulfur.

Gasmasks were necessary because of the very high SO2 concentration. It was also very hot.

And here is the final product:



1 Like

Very nice.

David R. Boulanger

That is awesome!
Thanks, Grant.

This is super!

What kind of sonar is it, single beam?


Here is a 5 min. video about the boat and the exploration of the Poas Volcano.




@gvr63 I am doing a similar project to map the depths of reservoirs. what software are you using to calculate the Surface Area, Depth and produce the map

Hello David

I use the affordable ReefMaster Pro software. Calculating area and depth is with an extra paying module.



Thanks that looks like software i am looking for


Do you get sonar data from a PC in the land through telemetry?
I have RS232 connection echosounder and PixHawk3. Do you know how I should connect them and set up to get the data on the land to generate a map in conjunction with GPS data? The echosounder can send NMEA format and just depth data.

Your help would be appreciated.

I would like to congratulate you for the excellent work, I apologize for my poor English.

I like how the Sonar LowRance Hook 4 works, does it have any connection to the APM? What data does it provide me later is it possible to transform them into a 3D map with REEFMASTER software?

Thank you very much in advance.

Hello Rodney

The Hook has an SD card. So all data is stored on this. There is also an NMEA port. With the extra connector you can obtain the data from the sonar real time and send it e.g. with telemetry to the shore.


Guy Van Rentergem

Hello gvr63.
Congratulation for your great project.
I notice that NMEA 0813 function is available on Lawlance hook 4.And I want to ask a question please,could hook 4 connect to pixhawk by NMEA 0813 cable,And will it work, Have you tried?
Forgive my pool English language.
Thank you.

This is a wonderful, simple solution, with off-the-shelf parts, to do a great mission! As a geographer and fresh RC enthusiast, I find this awesome! I also find it impressive that you managed to build a 10kg-ish AIR boat, with 2 hours of autonomy with just 2x 5000mah batteries! Damn! Keep it up!