On the Searunner
the center of bouyancy of the amas and main hull
is forward of center. This is also near the maximum depth
and beam of the hulls. As the main hull
runs aft it shallows out into a u shape. The amas are also a little asymetric in cross section to help counteract leeway. For a chined plywood
hull they are quite sophisticated in shape. This all goes a long way toward lessening the fore and aft pitching and giving the boat a very comfortable motion. I have never felt there was a lack of bouyancy forward. The box beam is also eliminated and replaced by a walk-thru mainstrenght bulkhead fore and aft.
I have liked the Simpson Liahona also, beatiful boat. Just never had the luck to see one in the flesh.