Ship stability
（重定向自Instantaneous stability）
![A model yacht being tested in the towing tank of Newcastle University](/Images/godic/202501/20/NewcastleTowingTank2616.jpg")
![A bilge keel](/Images/godic/202501/20/Bilgekeel2616.jpg")
![Illustration of the stability of bottom-heavy (left) and top-heavy (right) ships with respect to the positions of their centres of buoyancy (CB) and gravity (CG)](/Images/godic/202501/20/Ship_stability.svg2616.png")
Ship stability is an area of naval architecture and ship design that deals with how a ship behaves at sea, both in still water and in waves, whether intact or damaged. Stability calculations focus on the center of gravity, center of buoyancy, and metacenter of vessels and on how these interact.