DIY ROV

Months ago I decided I was going to build my own underwater remotely-operated vehicle. I got sidetracked by a kitchen remodel, but since it is now complete I will have some free time to start working on my vehicle. There are some decent videos out there where others have done the same thing, some are wildly complicated and others are basically built from items out of a scrap bin. I am hoping to land somewhere in the middle.

During the bit of research I have performed, I discovered companies selling very high-end parts, the likes of which you would find on a highly funded/sponsored deep sea expedition or a government project. I didn't find a whole lot of middle ground really, either you DIY or you dump a ton of money into it.

My plan is to use PVC for my hull. I had thought about constructing it similar to the Russian Typhoon-class submarine, with two pressure hulls within an outer hull. That would allow the electrics to reside in dry compartments while I use the void space for ballast. I even found RC submarine ballast systems on eBay which would allow me to take on water and dump it remotely so I could trim it out on the fly.

The general opinion, I have discovered so far, is to make it neutrally buoyant. As much as I would like to add that ballast tank system I may need to just keep it simple for my first attempt. Tethers also seem to be an issue, adding too much weight when they get to a certain length and if you do not take steps to make them buoyant. I thought pool noodles, but learned from someone else that they become water logged and are a bad choice. Then there is power, the trend I noticed is keeping it onboard in the form of a battery pack, but I would like to keep it ashore and just add a wire to the tether so I can not have power to worry about.

So far I have an Arduino board, some old laptops, and some rivers to explore. If we had a makerspace or hackerspace nearby I would be all set. I did search, and the closest is an hour away, which is disappointing since I know I am not the only person into ridiculous projects/hobbies around here! Anyone on here into things like this?