Rental fees at Long Beach's 3,754 municipal boat slips will be increased 5.75% Sept. 1. The City Council approved the increase at Shoreline and Alamitos Bay marinas, jumping rental costs from an average $5.89 per foot of the slip to $6.23 per foot. The council also increased its charge for "live-aboard" privileges granted 10% of the boats in city marinas from $53.50 to $65 a month. In addition, the cost of joining the 2,000-person waiting list for slips was increased from $42.50 to $75. Even after the increases, the rates are lower than at most Los Angeles-area marinas, city officials said.