Assuming the song you're looking for info on is "Rolling Home To Old New England", it certainly is very satisfying done acapella, but when I want to accompany it with my guitar, I do so in the key of A.

Here's how I hear it: [A]Call all hands to man the capstan / See the cable running [D]clear / Heave [E]away and with a [A]will, boys / For New [E]England we will [A]steer.

Just repeat that for all the verses (and there are many and varied).