Cruising the world’s waters doesn’t have to take a toll on the environment or, for that matter, on the pocket of the seafarer, with the only exception of the price he or she pays for the boat.

We recently gave you a peek at Silent Yachts’ Silent 55 catamaran that was on display at this year’s Cannes Yachting Festival. But the 55 isn’t the only model that the Austrian boatbuilder is working ...