lincolnr - Put your boat all up (with batteries) on a gram scale. The weight of the boat = the weight of displaced water. Use the gram per cubic inch ratio above to calculate the volume of the water you would need to offset. If you use closed cell foam of some sort don’t forget to add in its weight to your calculations.
Of course, the layman’s way would be just to fill up the front half of the boat with some light weight non-absorptive material. After all, most boats have more freeboard than immersed volume so you are bound to overcompensate with this method.
As mentioned before though, the best method to stay afloat is to build a waterproof boat!
That’s correct Niel. You can measure the (closed-cell stuff, like pool noodles or pink/blue construction foam) material’s capacity for displacement by the methods we discussed here, then add enough flotation to your hull. Don’t forget to leave room for sheets, pushroads, wiring and aerial(s.) You might even provide a channel for water to drain, just in case? :scared: :devil3:
Fortunately, water is dense enough so that a little flotation ‘goes a long way’ to keep the boat floating enough for a rescue.
I understand hydrostatics just fine. I just wasn’t sure what you were getting at. And no need for a gram scale if you don’t have one, as I mentioned. I’ll admit that I’d have to either ponder a while or look it up if I needed a good definition of metacentric height.
