In "The Shanty Book" Richard R. Terry writes:

Who Stormy was is undiscoverable, but more than a dozen shanties mourn him.

Joanna Colcord, in "Songs of American Sailormen" notes:

Bullen says of the next shanty, "it embodies all of the adoration that a sailor used to feel for a great seaman, gives it expression, as it were, though i have never been able to learn who the antitype of Stormalong could have been. I suspect that he was just the embodiment of all the prime seamen the sailor had ever known, and in this song he voiced his heart's admiration."

Keep those silver spades polished -- Tom