Trimaran have restricted mobility. Trimarans designed for safety have amas with multiple sealed partitions, controls that all run to the cockpit, a collision bulkhead, partial or full cockpit coverings or windshields, and drain holes in the cockpit that can adequately drain the cockpit quickly, among other things. Trimaran capsizes are more likely to be of the pitchpole type than a roll to one side due to their higher sideways stability and speeds. Capsized trimarans are harder to turn upright after they have turtled than monohull boats. While some capsized trimarans righted by sideways rotation may suffer heavy damage to mast and
Pontoon bridge consisted of one or more pontoons, which were maneuvered into position and then anchored underwater or on land. The pontoons were linked together using wooden stringers called "balks". The balks were covered by a series of cross planks called "chesses" to form the road surface, and the chesses were secured with side guard rails. A floating bridge can be built in a series of sections, starting from an anchored point on the shore. Modern pontoon bridges usually use pre-fabricated floating structures. Most pontoon bridges are designed for temporary use, but bridges across water bodies with a constant water level can