Scott, that is a good question... I am building a trawler cat that is intended to be most fuel efficient at 9-11 knots... I came to this boat from a back ground of being a rag bag, monohull sailer who was thrilled to see 7 knots for the day... It took a lot of reading and talking with people to convince myself a power cat was best for my wants.. (reasons not being rehashed here) The initial calculations showed 70 hp engines pushing it at least 18 kt. I am probably going to go with the Yanmar 127 hp units as there is no real weight penalty for the larger engines and with electronic fuel injection they will run efficiently at low speeds... The bigger engine will give me the ability to run against a head sea when needed... Speed is often touted with cats, and they are faster than monohulls in general... But there is more to the speed equation than hull speeds... I noted in one of the across the Atlantic group runs that a cat which was supposed to be able to run away from the fleet was no faster than the big monohulls in a rowdy sea condition - and in fact suffered some damage and had to go slow later on, but that is a quality issue, not a hull type issue... It is like the 36 foot rocket my son-in-law has that can run 40+ mph in the bay, but out on the big lake where 8 foot rollers are common we back it down to keep from getting our kidneys turned to mush - and you sure as hell don't want to take a cresting roller, head on at 40 mph... So, for cruisers who will live aboard, a 9 or 10 knot boat is fine if it is fuel efficient at that speed.. You do want the ability to run for port at something better when the weather goes sour faster than predicted... There a sailing hull that is limited to 9 would be a handicap and would not be my first choice... As far as the emotional wailing about the cat overturning, if the sea is that bad you shouldn't have been out there in the first place regardless of hull type... Given todays advanced weather imaging and forecasting, being caught offshore in a severe storm is the skippers fault, not the sea... I plan never to ever be out in those conditions, but I am also putting in escape hatches, just in case... In any event the boat will float even holed and completely flooded, which adds to my comfort level... As far as the knock that a cat is uncomfortable in a rough sea and a monohull is not - I see lots of emotion and zero facts... Seems most multihull sailors (power or sail) consider this a non issue based on experience, not based on what they read in some forum written by some guy who has never set foot on a cat in a real seaway...... At this point I am routing to final dimensions the last of the nearly 60 bulkheads that make up the hull mold... denny --------------------------------- Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains.