About 340 boats will be on display at the Newport International Boat Show, which runs from Thursday, Sept. 12, through Sunday, Sept. 15. But only a handful will be new cruising powerboats that are being shown in the U.S. for the first time. Here’s a look at some of them: Bruckmann Abaco 47 (pictured above):  Built on the success of the popular Bruckmann Abaco 40, the new 47, designed by Mark Ellis, is a classic Down East cruiser with a long sheer, low profile, sharp entry and raked windshield. Built for extended cruising, the innovative hull is designed to plane…