Thanks for the technical explanation of deadeye and deadman. I actually knew about the deadeye, but I don't quite see how one can make an obscene reference to it.
There are plenty of double entendres in sea songs. It must have been something that would break up the ennui aboard ship on long voyages. Personally, I like them.
The people at song circle know me as the lady who likes shantys. I am directing a children's choir this summer. You needn't guess what we're singing. Sea songs, of course. But cleaned up a bit: I want to have the option of teaching next year.