Here's another reference to "The Captain's gone ashore"/ "Grog time of day" that I don't think has been mentioned. It is from THE EVERGREEN, OR GEMS OF LITERATURE FOR MDCCL (1850), ed. by Rev. Edward A. Rice. The first "gem" is entitled "Quarter-Deck Yarns; or, Memorandums From My Log Book", by "An Old Salt". The setting is the "clipper-brig Curlew" in the New York Harbor, ready to sail for Hamburgh. During the night a favorable wind came up and and "the outward bound vessels were busied with preparations for getting under weigh."

The Curlew's anchor "had been hove short under the forefoot, her staysail and trysail were triced up, foresail dropped, mainsail hanging in the brails; and the topsails' loosened from their confining gaskets, were curtaining the caps with their snowy folds. When our boat came within hailing distance, the halliards were manned, and the good-humored crew run the yards up to the chorus of

   "The captain's gone ashore, but the mate is aboard,
   Hurrah! my jolly boys, grog time o' day."                         (pp, 10-11)

Here is the link:

http://books.google.com/books?id=ueQsAAAAYAAJ&pg=PA11&dq=%22the+captain's+gone+ashore+%22&lr=&cd=7#v=onepage&q=%22the%20captain'