Center nacelles on cats divert the water
that might otherwise slam a flat bridgedeck. It changes the noise
from a slam to a drum roll. It also slows the vessel everytime it dips into the water. It also provides additional storage
, room for a central engine
compartment or a foot well. It cost more to build. Short of extreme conditions, slamming is just an annoyance that compromises performance.
So: attention to slamming issues is required in performance oriented designs and is a secondary concern in cruising oriented designs. So are windage, light weight, sail area, hull
beam width, and so on. You don't need to be a naval architect to know the difference; if its a feature found on an Outremer
, its performance. If its found on a Packet Cat 35, its a motorsailing condomaran. If its as robust as a PDQ
44 or a Privilege
, its Rolls-Royce pricey. If its cheap
there's a reason.