Shipkeeper

… and when the ship is like the one now in question, not being navigated, but laid up in dock, there is the additional possibility that the shipkeeper may be the servant of the dock company, or the ship's broker, or any one else with whom the owners may have made an arrangement to keep his ship for him as a bailee of the ship.

Source: wiktionary

In the sailing ship days practically every ship had a shipkeeper, usually some wheezy old pensioner who had at last been reluctantly driven to the admission that he was too old to go to sea.

Source: wiktionary

The official was responsible for safeguarding the captured vessle by hiring a shipkeeper to oversee its maintenance and security.

Source: wiktionary