Y'a vs Yat: usually, this "t" is between two dashes, it's indeed to add a consonant sound between the "a" and the "u". It's the same as when we say "combien y a-t-il..." or "Malbrought s'en va-t-en guerre".
Le chasse-marée presently has 4 "cahiers" on sale (4 for €19.80), Coop Breizh has some stuff too.
Do you have such stupid sailors in shanties in English? I mean the guy who dives again and again till he gets drowned because he wanted to find any thing the girl said to have dropped in the sea? Because quite a few of ours were pretty idiots!