The U.S. Navy guided-missile cruiser USS "Cape St. George" (CG-71) refuels with the Royal Canadian Navy replenishment ship HMCS "Protecteur" (AOR 509) during exercise Koa Kai 14-1 in waters near Hawaii (USA). Koa Kai is a semiannual exercise that improves cooperation, readiness and the capability of forces to respond quickly to various crises, ranging from armed conflict to humanitarian assistance.