I have a friend that had a Mainecat 30 with Yamaha 9.9s and I did several trips to the
Bahamas from
Florida. The Mainecat has
engine mounted amidship and cavitation was not a problem, on the other hand an acquaintance with an Endeavourcat 30 with the
engine mounted near the stern said his cavitated all the time. That said, the only serious issue we were aware of with the engine Yamaha 9.9s on the Mainecat was a nearby
lightning strike (hit the
water,not the boat) that took out the
electrical system on one of the engines. At the time one engine had been lifted out of the
water and was not affected. I imagine if both engines had been down he would have
lost both of them as the
lightning strike was on the opposite side of the
boat from the dead engine. Being a sailboat he was not disabled but it make for some sporty
docking. I've personally had a couple of nearby strikes while
offshore so I would think twice about being offshore in a
boat with an engine that could not even take a nearby lightning strike. I suppose that includes modern diesels with engine
computers.