Trimaran to the main hull. This allows them to be trailerable and/or to fit in a normal monohull space in a marina. At least six technologies are in use: Although it is possible for a trimaran to capsize, this is less frequent than with monohull boats because of the greater resistance to rolling that the amas offer. Most trimaran designs are considered nearly unsinkable because even when filled with water, the buoyancy of one ama is enough to keep the entire vessel afloat. Because of their stability and safety, special trimarans such as the Challenger have become popular with sailors who
Pontoon bridge Earl of Shrewsbury crossed the Oise river across a pontoon bridge of portable leather vessels in 1441. Ottoman engineers built a pontoon bridge across the Golden Horn during the Siege of Constantinople (1453), using over a thousand barrels. The bridge was strong enough to support carts. The Ottoman Army constructed a pontoon bridge during the Siege of Rhodes (1480). Venetian pioneers built a floating bridge across the Adige at the Battle of Calliano (1487). The Spanish Army constructed a pontoon bridge at the Battle of Garigliano (1503). The Spanish Army of Flanders under Alexander Farnese, Duke of Parma built an