The hull design has a natural stability due to its hard chine, deep keel and equal weight distribution which enhances the dynamic stability.
Stabilization is enhanced with the stabilizer booms, the birds and with sails.
All fuel tanks are located around midship and below the waterline, minimizing trim changes as the fuel is used. The stern water tank can be used as fore-aft balance.
Stabilization is increased with the booms deployed and further increased by deploying the birds from the booms. In addition, the clip-on headsail and mainsail can be used for stabilization and propulsion.
Large scuppers limit the amount of water-on-deck and the 2 side deck doors can be removed to further increase the scupper area.
This Sedan has a full width salon, which further minimizes the water-on-deck area. This is explained well by Bill Kimley in his description of the Seahorse Sedan 462:
The wide body design, without any side walkways, is actually more safe, seaworthy as down flooding, when severely heeled, and the chance of shipping a lot of water in rough wave situations, are lessened.