QuadFloat - Float Your Drone or Quad

I wanted to fly over some pretty deep water in situations where a rope or large jets of water might take out my quad. The quad is largely made up of junk parts, so I don't care too much about losing it. That being said, the GoPro is not something I'm willing to part with that easily and littering a lithium battery and whatnot into the lake is something I'd like to avoid.

The formula I used was to weigh my quad with everything attached (including the float) in grams. Find a bottle with an equivalent number of of ml (which is equivalent to cc's or cm^3) + 15% or so. A displaced ml of water weighs ~1g and I believe you'll need to displace about as many grams of water as your quad weighs plus some. If you float only as many g as your quad weighs - the quad won't float as much as touch the surface ... so you'll want a little extra floatation to keep it on the surface. In my case the nearest bottle size that was close to my limit was 23.7oz or ~700cc.

I'm ignoring the water that