Custom ROV for sea currents

Hi everyone,

I share a new design developed for a client who sails in waters with a lot of sea current.

The design is compact, with thrusters, batteries and electronics in a single plane to have the best possible hydrodynamics but with a strong structure so as not to give up robustness.

The flotation system is high density polyurethane foam machined in cnc and coated, with a narrow and hydrodynamic design.

It has a double parallel battery system of 12,000 mah each, in total 24,000 mah to be able to work without energy problems or battery overheating using the ROV at 100% gain for a long period.

It incorporates an on/off switch that cuts off all power to the ROV, a 4k motorized varifocal camera at 20 fps or 30 fps with a slight reduction in image size and 0.01 lux of minimum color illumination, zoom control, focus and image capture with the joystick.

I leave you a link to see some video of the first underwater images and the speed of navigation. (download to watch with quality)

We are very happy with the result, I hope you like it and get ideas from the design.

Best regards


very nice mate!


That’s beautiful! Well done!

I see you have a different camera in the dome and I’m interested what it is if you’re willing to share.



Very cool build indeed! Looks like to me they are using an ELP H264 USB camera with a zoom lens that can do autofocus and zoom.

I’ve experimented with these in the pasts but they tend to lean a bluish tint in their color science.


Well done! Any information on how many knots of current it can work in?

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What do you use to control zoom and focus with BR2

Sorry for the delay, I’ve been very busy these days. Thanks for the feedback!

The camera is a 4k ip module with a Sony imx415 sensor, with a 5X motorized varifocal lens and a focusing board for its control. It can also be used with a fixed lens.

What I like the most is the image quality and automatic color adaptation, the colors are vivid and beautiful with great definition in the details

I use ip cameras because in my opinion usb cameras, working through raspberry Pi 3B, cannot reach 4k resolutions with high data rate since this Pi board is not powerful enough and therefore the images are not good enough. Therefore, on board the ROV I use the BR ethernet switch with one fathomX or two fathom Xs in the ROV and one on the surface, both systems work fine, I’ve tested it with up to 200m of cable. In addition, currently most ip cameras use ONVIF protocol and H265+ HVEC compression and this allows you a high data rate speed and use them with different software for use and control such as recording or taking photos.

For joystick zoom and focus control, you can use the pelco D or P protocol and third-party software such as

The only thing I don’t like about the varifocal lens that I installed on the camera is that the zoom speed is somewhat slow, compared to the previous two motorized varifocal lens cameras that I have already shared in other previous posts (link attached to see speed zoom from the previous ip module: module ip 4k 15 fps fast focus - Google Drive )

However, the focus, being slower and having a long range, is perfect for focusing on objects and defining them perfectly even at minimum distances, practically glued to the lens. Despite this, I am investigating to install another faster motorized lens, as soon as I have it 100% ready I will share it here.

For streaming with Qgroundcontrol I connect via rtsp, but it is important to know that you need a good workstation or pc (minimum example: i7 with quad core and 8 threads with 2.8 ghz and turbo 3.8 ghz, 16 g RAM, ssd disk and Nvidia Quadro 2GB or higher dedicated graphics card), otherwise there will be image lag. With this workstation, using several software at the same time, I get a simultaneous connection via web browser and via Qgroundcontrol both in 4k at 20 fps with a delay of less than 0.2 seconds.

Regarding the sea current, the ROV was designed for an area with currents up to 3.5 knots. The first test yesterday went well at 25% gain but the current was not higher than 2.5 knots. This week we will do more tests but the sensations of the compact design of the ROV are very good.

Finally I share detail of the lateral opening system of the sealed tube of the batteries

Best regards.


Thanks, @Andres, for all the details. Very impressive. It’s definitely nice to use an IP camera and eliminate the need to pass video through the Raspberry Pi.

Very nice design!! Would you mind if we shared about your vehicle on Blue Robotics’ social media as well? Thank you!

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Thanks @rjehangir ,

I have worked from the beginning with IP cameras in my ROVs and after 5 years it seems to me the best and simplest way to have a very good image quality without affecting its operation.

I am very happy with this latest camera for its size and quality, and I am considering making a model for those who are interested, with the structure and servo ready to install in the standard electronic tube without having to do almost any modification, plug and play. It would incorporate a new fast zoom and focus system that I am already testing.

What would be really interesting is to be able to access by onvif protocol through Qgroundcontrol instead of rstp, and thus control all the parameters of the IP cameras with a single software.

I’m going to wait for you to publish the new 4" waterproof tubes with safety locks in case the dimensions are altered.

best regards

Hi @kristelhall ,

Of course you can share it, I’m glad you like the design!


You may be pleased to find out that we’re currently building that functionality into BlueOS - the camera manager will allow onvif-based configuration of IP cameras on the ROV’s network :slight_smile:

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Hi @EliotBR

That is great news, I look forward to its implementation.

It would be very good to incorporate several profiles for ONVIF, g, s and t are the most used so there will be greater compatibility. On the other hand some softwares also allow ptz control via joystick (xbox 360, logitech F310 and F710) with onvif, even recording and taking photos, that would be great too.

Good luck in this difficult task!

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Thanks for the suggestions - I’ve passed them on to the software team :slight_smile:


Are you going to sell these models and if so how much and when?
Can you add 2-more batteries for total of 4?
Plans for any upcoming Blue ROV upgrades?


Hi Mark

The ROVs are made to order according to the needs of the client. Being personalized projects, the price depends on the hours invested in the development of the equipment, its components, number of batteries, the length of the umbilical cable, type of camera, transport case, etc.

I developed this model for a company that has a tourism project in waters with strong currents. The tests carried out to date in conditions of 4 knots of maximum current have been very satisfactory, since a very good control of the ROV has been obtained using 50% gain on the surface and 25% near the seabed.

Regarding your question about the 4 batteries in parallel for this design, I don’t see it as viable since there is not enough space. With another larger design that I have made, 4 batteries can be included in parallel, but due to hydrodynamics and the power of the T200, it does not behave as well with strong currents. In other words, you gain load capacity and space but lose efficiency.

On the other hand, the ROVs in which I include the batteries are only sold within the EU, since current legislation does not allow me to export to the US, for example.

If you have any other questions, you can write to me at

I don’t quite understand your question about the next BR2 updates, I think it’s not me who should answer but the guys from Bluerobotics.

What I can say is that I am about to finish the development of a high quality 4k IP camera, with a very wide servo movement and a high speed motorized varifocal lens that allows control of zoom and focus with the joystick. I think this camera will be an important improvement, in fact I have designed it so that it can be installed in any BR2. As soon as I have the prototype ready, I will show it here so that interested people can contact me.

Best regards


Thanks Andres,
I think the BR3 with the T500 thrusters is coming out in 2024, but I would like a 4 batt version as well as top side 110v power…I do inspection work. A 4K camera is a must, grabber, altimeter annd at least 2 more ports for other sensors and wired for Cygnus UT gauge…maybe a pair of green lasers also. Just keep me informed.