There are a variety of types of stability but except for dynamic stability, they all derive from the horizontal athwartships distance between the center of gravity of the boat and the center of bouyancy of the boat in the heeled position. In the case of a trimarran the leeward ama moves the heeled center of buoyancy outboard at a rapid rate generating a lot of stability. This type of stability is called ''form stability''. Form stability allows a lot more stability at small angles of heel for any given weight of craft, but it comes at a price in terms of more rapid and therefore less comfortable motion, and also as the heel angle increases above comparatively small angles stability decreases rapidly and the likelihood of a capsize increases. Once inverted a high form stability boat is likely to be extremely difficult to right again.