Undock

v. [UN-² 5.] trans. To take (a ship) out of a dock; sometimes spec., to launch.

1750.  Naval Expos., 15. On docking and undocking Ships.

1804.  Trans. Soc. Arts, XXII. 277. Enabling large ships to be docked, suspended, and undocked, the same spring tides.

1897.  Westm. Gaz., 30 Sept., 5/2. Before the Lynx could be docked it was necessary to undock … another destroyer.