I wouldn't place too much credence in John Holland being the author of this particular song, since there was at least one other "Sam Spritsail" song which predated it (1805), and likely others. I gather that Sam Spritsail was an occasional moniker for a tar. He appears as a character in some later stories, mostly set at the Battle of Trafalgar--Google Books now turns up several of these, as well as the earlier song I mentioned. He also appears in Thomas Dibdin's musical production Romeo and Juliet (1832?), along with characters named Ben Bowsprit and Tom Tackle--names lifted from his father's songs--, so it's not unlikely Charles Dibdin wrote some song named "Sam Spritsail". He did write a song titled "Sam Splicem".

"The Mariner's Compass" was collected in The Universal Songster (Volume 3) at least by 1826. This seems to be the earliest firmly established date for the song, from the sources unearthed so far.

Frederick Marryat quoted the chorus in his book Jacob Faithful (1831). Since the earliest unequivocal mentions of the song appear clustered in the early 1830s (as are most of the stories), it seems likely to me that this particular song was written not much before. I suspect it was one of Charles Dibdin, Jr's, whose writing style was more music-hall (or beer-hall) than opera-hall. Consider his reuse of the character Ben Backstay.