29 CFR §1926.606

1. (a)Apron—The area along the waterfront edge of the pier or wharf.
2. (b)Bulwark—The side of a ship above the upper deck.
3. (c)Coaming—The raised frame, as around a hatchway in the deck, to keep out water.
4. (d)Jacob's ladder—A marine ladder of rope or chain with wooden or metal rungs.
5. (e)Rail, for the purpose of § 1926.605, means a light structure serving as a guard at the outer edge of a ship's deck.