They converged on the city centre from Howth, Bray, Dun Laoghaire and other parts of the east coast served by the DART.
But there was only one way to travel in Dublin yesterday and it wasn't in a train carriage.
A blue sky, a calm sea and just enough breeze to swell a canvas made it plain sailing for the Cruise-in-Company 2000, which brought hundreds of water-borne commuters into the mouth of the Liffey in aid of the Irish lifeboat service.
It was only the fourth such gathering of the greater Dublin boating community, following similar events in support of Live Aid (1985), the Dublin Millennium (1988) and the European City of Culture celebrations (1991).
And the man who organised each of those occasions - the admiral of the fleet, Mr Eamon Markey - was again on hand yesterday to watch the parade of sail.
Only just. He ran into choppy waters early last week when he was hospitalised with a urinary tract infection - "the worst pain I ever experienced". But he was out again by Saturday and clearly in ship-shape as he oversaw the invasion from the bridge of the Naval Service flagship, the LE Eithne.
It was "anybody's guess" how many boats were involved, he said, estimating the figure at more than 500 and hoping the sponsorship drive for the RNLI would at least equal the £20,000 previously raised by the event for the St Vincent de Paul.
The craft taking part, which ranged from 60 ft yachts down to punts with less canvas than a two-man tent, moored in the Liffey for picnics and other celebrations. But it was a short-lived invasion. As the tide ebbed in mid-afternoon, the flotilla turned around again and headed out to sea.
All shapes but, happily, no capsizes.
