Hey Mike,

I'm no expert, but enjoy reading about boat building so I'll take a stab at this based on what i know -- I think that you most definitely can build a 350 lbs. hobie 18 that is just as durable as the 420 lbs. version. Some people have started to touch on this but here is alittle synopsis of the racing boats construction. Most modern lightweight boats are made with a 1/4" foam core with about 10-15oz of glass on either side of the core (Hobie tiger, Nacra 20, 18 etc...). I would look at two methods to try to build lighter, but just as durable 18.

Option 1. Use a cored laminate for the hulls. I would try something like a 6 lbs/Cu. Ft. balsa core. It is still pretty light and has considerably more compression strength than foam. It is a bit more difficult to work with however. I would then use epoxy resin and S-glass for the laminate (say 3 layers of 6oz S-glass for the outside and 2 layers of 6oz S-glass for the inside). You could also try substituting 1 layer of glass for kevlar, but only on the inside. I would also vacuum bag the laminate to get the resin content down on the laminate.

Option 2 - use monolithic laminate with stringers for stiffness. basically use the method as the original 18, but substitute s glass for the e glass and epoxy for the resin. use about 20% less glass for the laminate schedule is use either wood (cedar), balsa or foam strips to make stringers (both vertical and horizontal) on the inside of the hull. have these covered with the last 1 or 2 layers of glass. again, vacuum bag to get the resin content down.

I think doing either of these methods, you can probably reduce the weight of the hulls by 20-25%. I'm guessing the hulls weight around 120 - 130 lbs. each so you would be getting a weight savings of around 50-65 lbs. I doubt you could get much more out of the hulls without sacrificing durability so I would then look to the rig. replace the tree trunk of a stick with a slightly overbuilt carbon stick and that should give you another 15-20 lbs. This would be a considerably more expensive way to build a boat - materials are about 10-20% more, labor would more for the vacuum bagging and cutting the core/stringers. Either way, a fun question to ponder.

anyone got some Hobie 18 molds we can play with??

cheers.