Canoeing -- Mount Desert's ponds offer scenic if limited canoeing; most have public boat access. Canoe rentals are available at the north end of Long Pond (the largest pond on the island at 3 miles long) in Somesville from National Park Canoe Rentals (tel. 207/244-5854). The cost is $22 for 4 hours. Much of the west shore and southern tip are within park boundaries. Jet skis are banned in the park, and swimming is prohibited in ponds that serve as public water reservoirs (including Bubble, Jordan, Eagle, and the south end of Long Pond).