It could be Off the West coast of Ireland one morning there was seen
As plain as a pikestaff a German Submarine

I can't remember the next two lines

He jumped from the harbour as frisky as a whale
He swam up to the U-Boat and wagged his little tail
He up with his horns and he stuck them in the boat
and he sent the Hunns to Helegoland did Paddt McGinty's goat Bheers Bill