Dolphin

An isolated marine structure used for mooring, berthing guidance or protection.

A dolphin may be formed from a group of piles, a rigid column or a caisson. Mooring dolphins carry fittings to which lines are secured, while breasting dolphins provide a contact face that helps position a vessel alongside a berth. Protective dolphins can shield bridges, locks or other structures from impact.

Unlike a continuous quay or pier, a dolphin normally stands separately in the water, although it may be connected by a walkway. Its charted position, lights and markings should be observed carefully because it can also be a substantial navigation hazard.