KOGE MARINA, Denmark (AP) — From a distance they look almost like ordinary sailboats, their sails emblazoned with the red-and-white flag of Denmark. But these 10-meter (30-foot) -long vessels carry no crew and are designed for surveillance.Four uncrewed robotic sailboats, known as “Voyagers,” have been put into service by Denmark’s armed forces for a three-month operational trial. Built by Alameda, California-based company Saildrone, the vessels will patrol Danish and NATO waters in the Baltic a...