Bob, I can only comment on what we go through on the Buzzards Bay 34's to balance weight between outboards and diesels, as we are not yet that far into the design spiral on the 40. On the 34, we do not use the Yamaha 350 V8. It's too heavy, and we do not need the power. We stay between 225HP and 300HP, which means about 700 lbs each back there. The total installed weight is about 500 Lbs less than a pair of Volvo D3's with duo-props (factor in engine beds, transom assembly, sound proofing, etc.), but the change in weight placement does shift the LCG forward by about a foot and a half. We balance this by shifting some of the fixed weight equipment (ex: batteries) aft, and are further aided by the fact that diesel boats tend to get our very nice dinghy davit set-up at the transom. It doesn't take much to get the balance back to where we like it. Before each build, we locate all the equipment and options, and plug the weights and locations into our LCG spread sheet, so we know exactly what is going on. Interestingly, the way owners stow gear can have a bigger affect on LCG than the diesel vs outboard selection. > Russell, > > Thanks for the insights. As a builder, how do you adjust for the weight > distribution between inboard diesels and outboards? Two Yamaha 350's > represent about 1,700 lbs hanging off of your stern. > > Do you have to adjust the hull design or interior configuration to maintain > trim? > > Bob Deering > Juneau, Alaska > -- Russell Hunt, President Multihull Development, Inc. and Buzzards Bay Catamarans Office #: 508-403-0301 Cell #: 508-759-4111 Email us at: info@MDcats.com Check out our website at : www.BuzzardsBayCats.com http://www.yachtworld.com/multihulldevelopment/