A response to Len Sussman:- Captain Len is quite correct. A consequence of running a "normal" displacement hull ie: usually a sailing catamaran hull, at planing speeds, is that it "squats". The water flow at the stern "sucks" the stern down. The motor cat appears to be using a sailing boat hull form. However the "CS" hull form which we developed in 1983 and which is now used by a large number of other power catamaran designers, does not squat. You can see boats on our web site travelling at planing speeds [Froude number of more than 0.4]in quite level trim. The "Red Diamond" is travelling at 31.5 knots over the measured mile and the "Escape" is travelling at 25.5 knots. I have discussed this hull form issue in a number of articles. Regards, Malcolm Tennant. Malcolm Tennant Multihull Design Ltd PO Box 60513 Titirangi, Auckland 1007 NEW ZEALAND ph +64 9 817 1988 fax +64 9 817 6080 e-mail malcolm@tennantdesign.co.nz www.tennantdesign.co.nz www.catdesigners.com