John, I agree that there is certainly a case to be made for wider bodied hulls in some situations. You are assuming that the use of the CS hull form automatically means a high L:B ratio. This is not true. You can use the CS hull with any fineness ratio although it does tend to be associated with L:B ratios of at least 10:1. However there is no reason why it cannot be used with L:B ratios of 8:1, or less if you wished. and in fact has.What is more important hydrodynamically, than the L:B ratio of the CS hull is the considerably decreased appendage drag and enhanced propeller protection that it affords. This appendage drag could be decreased even further by getting rid of the rudders and using the electronically controlled engine rpms to steer. Unfortunately this would probably preclude the use of one engine and the classicication societies are less than enthusiatic about the idea. As well as those designers choosing not using the CS form are in fact a large number of designers who are using the CS hull form:- In the USA Manta is not alone; PDQs latest offering has this hull as does the new [and very impressive] Maine Cat. Photos of the Maine Cat show a hull that is a dead ringer for the hull of the Escape and that should be very efficient. I look forward to seeing some controlled fuel consumption and performance tests of this boat. In Australia:- Chamberlin, Schionning, Lidgard,Grainger and Brady all use the CS hull form and I suspect there are a few others. Aside from Derek Kelsal and myself, the CS form is used by Gavin Cooke and Richard Mcbride and Allan Walker are producing commercial designs in alloy with the CS hulls. Horses for courses! Regards, Malcolm Tennant. MALCOLM TENNANT MULTIHULL DESIGN LTD PO Box 60513, Titirangi. Waitakere 0642 NEW ZEALAND Ph: +64 9 817 1988 e-mail: malcolm@tennantdesign.co.nz www.tennantdesign.co.nz www.catdesigners.com