"Is there a date on the Blake reminiscence?"
Not as far as I know - this is the extract.
Jim Carroll

"How relevant, then, is the shanty to the Irish tradition? One can only speculate at this stage, but shanties were certainly not unknown to the Irish. The late Henry Blake of Kilbaha, in Loop Head, County Clare, had this to say:

Henry Blake: Sea shanties ?

Tom Munnelly: Aye. Now where did you hear them?

HB: Oh I heard them singin' them alright, you know. Santiago an'... It is with sailors I heard that; Santiana . . . Sally Brown, Homeward Bound, Goodbye Fare Thee Well. I remember them alright... Of course we were young and [didn't] take much
notice. But I have a memory of them. I heard the sailors on board the ship. ... So young Brennan [a pilot] and I took the captain off the Shannon, and Michael Brennan put him on board the ship. And they started to weigh anchor. And when they started to weigh anchor they started to sing the shanty Homeward Bound for Limerick Town.

TM: That was the same one as Goodbye Fare Thee Well was it?

HB: Yes, yes . . . It was lovely to listen to them. Of course they'd all [be] lovely singers, and ten, fifteen or twenty of them together singin', you see, 'twas lovely to hear them. I. . . very often heard them on the Island [i.e. laying off Scattery Island] when the ship'd be weighin' anchor on Scattery Roads. I wasn't out at all on the ship, but you could hear them on the island. You'd love to listen to them.

This recalls O'Curry's account of listening to Anthony O'Brien who shared a boat with his father on the same stretch of the Shannon estuary. The young O'Curry would stand on the shore to hear O'Brien singing Fenian lays:

So powerful was the singer's voice that it often reached the shores at either side of the boat in Clare and Kerry and often called the labouring men from the neighbouring fields at both sides down to the water's edge to enjoy the strains of such music".