A dock from which the water may be removed for the purpose of inspecting or working on a ship's bottom; it may be either floating or built into the shore
Compass (The National Training Portal of The U. S. Naval Sea Cadet Corps), appendix I, Glossary, VA, USA 2012. http://compass.seacadets.org/pdf/nrtc/bmr/14325_in d.pdf, (Mrtm/Nav - Amer) {558}