See version 1
In this version I threw out the enclosure and the PCB design of the first version. I wanted a device that looked half-way decent. The cable situation in V1 was also really not in a good place.
I thought that one interesting idea might be to create an inflatable enclosure. It could potentially mean that a majority of the enclosure could be made from cheap rubber inner-tube. Adding air pressure would:
What I learned was I was wrong about any of these being a real benefit.
Also, one big learning was that I never calculated the buoyancy of my device. It turns out that even with the entire enclosure totally deflated there was not enough mass to pull it down and have it float the way I had intended. I would need to add about a pound or more of ballast to the bottom to get it to float. Even then, it did not float up/down but instead kind of listed to one side like some half-dead fish.
Here's a materials list in gDrive. See the tabs at the bottom, select V2.
Here is a test-fit of the PCB in the 3D printed cap. I designed the lid with a board slot and pull tabs that snap into place over the holes in the PCB. Fits perfectly. Digital manufacturing is amazing.