The design details also include 3 watertight compartments, one for each cat sponson and a third under the level floor. In use, these compartments act like a double bottom hull in severe impacts keeping the hull watertight.
Interestingly the US Coast Guard does not allow these watertight compartments to be counted in its level flotation testing or stability testing.
So, in addition to the watertight compartments your Carbon Cat also has 3” thick closed cell EVA foam (same as used in life jackets) bonded to the inside hulls. This combined with EVA motor flotation blocks at each stern and the Sea Deck foam fender material allowed the Carbon Cat to meet all US Coast Guard flotation requirements with all three watertight compartments open and filled with water. These tests were performed in Aspen’s test tank with multiple concrete blocks
