Comparison of comfort and workability on board a trimaran and a monohull yacht

This paper discusses the possible merits and disadvantages of a trimaran over a monohull yacht. The powering performance and ship motion behaviour are evaluated for a modern 60 m monohull motor yacht and a trimaran with comparable displacement and installed power. Special emphasis is put on discomfort related to vertical and transverse accelerations. It is concluded that an increase in speed of 2 to 3 knots is possible for the trimaran. Comfort and workability on board a trimaran are superior over a monohull when sailing or at anchor in head seas. In quartering seas, the roll motions and transverse accelerations of this particular trimaran showed to be less tolerable than of the monohull. If these can be solved with special attention to the design of roll stabilising appendages, a trimaran can be a worthwhile option for owners who need a large deck area or who wish to stay onboard a longer than average period of the year.