While doing a little spot of research, I stumbled on this film of Aran Islanders from 1924, which I will add to the main Aran FAQ later.
Notes as I was watching.
The layers they wore, with the majority sleeveless.
I wonder if they had waterproofing on those trousers, otherwise wading into the surf like that could be very cold later.
The women seemed to have fabric shawls, woven over knit or crochet.
The men appeared to be wearing gansey style jumpers, and when you think that the Irish for jumper is Geansaí... it's not a huge leap of faith
One kid was wearing a white jumper that could have cables, but it was out of focus
and then I started to look at those waistcoats and remembered another semi-forgotten Irish garment, the Bainin Coat, the one that got Pól Ó Foighil into trouble and which I can't get an image easily of.
Another rabbit hole to get caught in