Coaming is a nautical term which refers to any raised surface along the edge of a ship or boat. It limits the amount of water that enters the boat through any opening. This can include a hatch, doorway, or vent. Coaming can also refer to padded surfaces along the railing of a large sailboat or yacht, in order to minimize the volume of water taken on by the boat. The term has also been used by the aviation industry to describe any raised barrier around the edge of a plane's unenclosed cockpit.
This term is used most often to describe a vertical barrier found around the hatch of a boat. A raised structure, such as the one found around the cockpit of a kayak, is also known as coaming. Recently, the term has made its way in to the sports fishing industry, where it is used to describe pads placed along the top and inner edge of a boat's railings. These pads are water-resistant and are used both as water protection and to lean against while fishing.
Boat coamings can be made of a variety of materials. On a traditional Greenland kayak, for example, the coaming is made of bent wood. In order to accomplish this, a straight piece of wood is placed in a steamer tube until it absorbs enough moisture to bend without breaking. A template is used to hold the wood in the desired shape. The wood is clamped onto the template until dried. Depending on the intended use of the kayak, the coaming can be attached to the upper edge of the cockpit opening, or strengthened with the use of a wooden support.
Coaming pads, which are designed for sailboats and sport fishing vessels, were originally made out of vinyl. They would typically be attached to the inner edge of a boat's railing by using plywood sheets. This required drilling holes into the inner hull of the boat. Over time, the vinyl would rot and mildew, and often had to be thrown away.
New coaming pads are made out of ethylene vinyl acetate (EVA) foam. This foam is waterproof and is resistant to ultraviolet (UV) radiation. Many of the new pads available do not need to be attached to a plywood sheet. Instead, they feature a simple peel and stick system which minimizes damage to the boat. Coaming will vary in thickness and cost depending on the grade purchased.