Re: Aluminum boats with flotation, any US manufacturers?
Hi Speaker. Many/most manufacturers of aluminum boats in the US use closed-cell foam flotation of some kind, rather than an empty "air-pocket" design you're describing. Often times the foam is installed under bench seats, the deck and/or in special designed compartments in the rear corners of the boat. You want/need foam, or a nonabsorbent material of some sort to crowd out any water that may find its way into the chambers, which WILL happen eventually, given enough time. Without foam, water would simply accumulate in the chambers, become trapped, and eventually sink the boat. Bare in mind, that unless you have an entirely foam filled hull such as Boston Whaler, or similar design, the flotation is only designed to keep the vessel from becoming completely submerged should it take on water. It will, however, still sink to just and inch or so above the waterline allowing it to still be bailed out eventually. While most vintage boats were not required to have flotation foam, I believe all modern vessels made in the US are required to have a certain minimum amount. Do a search here in the forums and you'll find all kind of clever flotation solutions ranging from pink/blue insulation board to, sealed plastic bottles placed below decks.
