So we have the Nottingham, with Captain Saumarez, who was not Irish.
We have Captains Somerville who may of may not have saiiled on Nottinghams.

And according to the Coppers the ship mysteriously changes name in mid voyage.

Mind you, that sounds back to front- the drift of their thing suggests that the French ship was sailing under British colours.

I had a search for the song as written by Saumarez, without success. Any chance of a repost?