Hi Garreth Hi Rolf

In the context of cruising cat design with the desire to extend areas out and up to obtain standing head room and galley head berth storage accomodations plus dining tables and mechanical rm -engine comp. etc this is an important aspect of design ,--its a nice looking cruising cat ,
Many older designs have accomodations between the hulls in the bridgedeck and some with flying bridgdecks above that ,--whew -lots of form windage .

Like this C Class designers comments -
The specifics of each type of design very much a blend of engineering research and applied science along with intuition ,insight based on experience and an funcional artistic ability.

http://www.lacaustralia.com/design/challenge.htm

and this one on the basics of righting moment -stability etc -
http://www.steamradio.com/JSYD/Articles/NESTalk.html

great 4 hull design Gareth , congrates again