For sea shanty songs I would say i am pretty limited on my choices as the only ones i know is "Blow the man down" or "Cape Cod girls" without bringing out the beach boys and "Sloop John B" or Jimmy Buffet and "Son of a Son of a sailor" or 'Boat drinks"
my knowledge of Irish Shanty's is even worse as i don't know any at all. I do however know a few irish drinking songs: "Whiskey in a jar", "Finnegan's wake" and of course "Beer, beer, beer".
P.S. Do you know where a drunken Irish sailor goes for a vacation?
A different bar! lol