Sorry about not being much help on the translation - but you're fairly charitable to Napper Tandy in your account. His 'landing' apparently finished with him having to be carried back onto the French ship - as he was too roaring drunk to manage it himself - the last throw of a fairly farcical character all round. My Irish is too bad to even know what a 'bacach' is (a 'tramp'?)- but 'síol Andaí' I'd reckon to be 'of Andy's seed' or 'of the line of Andy'