The city marina will lose one of its biggest tenants at the end of the month when the U.S. Customs Service's lease expires. Customs will give up eight of its nine rooms, where about a dozen investigators have worked the past five years. Last fall, officials said those people would be moved to Customs regional headquarters in Tampa, but that boats and boat operators would remain in Clearwater. Customs will keep one room for storage, according to a city memorandum. If the City Commission approves the new lease next week, the city will charge $9,150 a year for the 183-square-foot room. Under the old lease, Customs paid $19,200 a year for nine rooms.