This weapon, favored by aquatic elves, employs a special kelp string that dampens vibration and turbulence. The aquatic longbow functions as a normal longbow except when sea arrows are fired from it underwater. In this case, the weapon fires with the listed range increment and no penalty for being underwater (ranged attacks underwater ordinarily suffer a -2 penalty on attack rolls for every 5 feet of water they pass through). Mighty composite versions of the aquatic longbow are available, costing 600 gp for +1, 700 gp for +2, 800 gp for +3, and 900 gp for +4.