When you're in the business of making $3-million personal luxury submarines, you need to do everything you can to broaden the market. The first sale at Triton Submarines in Vero Beach was an international one, and international customers now make up half to three-quarters of Triton customers, says Vice President Marc Deppe. Predominant offshore interest usually has been from Western Europe, but the company has seen increased interest from Russia, Japan and, of late, Belize. Its new charter business, officially launched at October’s Fort Lauderdale International Boat Show, has its first deal booked: A client wants a Triton for an Antarctica trip.