This summer has been a good one for the U.S. yacht builder Palmer Johnson, which recently launched the second boat in its PJ 170 Sportyacht line and the first example of its futuristic PJ 48 M Supersport series.

The more classically styled of the two new yachts, the PJ 170 features architecture with a gentle, uninterrupted curve that extends all the way from the ship’s stern to its forward superstructure, where it meets the aggressive, angular bow. In a signature design feature of the Sportyacht line, the a…