The captain of a supply boat was arrested on suspicion of drink driving after his vessel ran aground in Anchorage's small-craft harbor, police said.It appears to be the first case of an alcohol-related marine accident at the port of Anchorage in recent memory, said Lieutenant Dave Parker of the Anchorage Police Department.The vessel, a 53-foot cargo craft, was steered up onto the harbor's concrete boat ramp, where it was left "high and dry," Parker said.On its way into port, boat also appeared to have struck and damaged an offshore piling, he said.A blood-alcohol test of the captain, Albert Anderson, 57, revealed he was at least one-and-a-half times the legal limit for operating a motor vehicle or water craft, Parker said.Police are treating the case as a routine drunken-driving incident, albeit one that does not involve a car, he said.No oil spilled and there were no injuries from the accident, Parker said.