VANCOUVER, British Columbia (AP) — Five British nationals died when a whale watching boat with 27 people on board sank off Vancouver Island, the British Foreign Minister said Monday. One person was missing and the rest were rescued, some by members of the local aboriginal community who rushed to the scene.The vessel made a mayday call late Sunday afternoon on a calm, clear and sunny day off the tourist community of Tofino, a popular destination for whale watchers, the Joint Rescue Coordination Centre said.The cause of the sinking remained a mystery.