OK my thinking is incorrect, so if more weight further away from the center doesn't help with righting moment, why do sailors hike out or trap out for that matter????
The thing to understand here is both trimarans and catamarans are symmetric relative to their centre lines. Meaning one side of the boat is a mirror image of the other side when viewed from the centreline. If weight is moved away from the centre then an equal amount will be moved away in the other direction. The net result is that the centre of gravity remains were it was, on the centreline itself. So nothing changes in the righting moment of the total craft.
Crews on the other hand do not follow this Mirror image principle. They are either on one side or the other and so DO affect the total amount of righting moment.
Wouter
