As of 1pm, some 12 of the 30 people on board the training vessel had been taken off to nearby Kinsale as the ship lists in the waters at Oysterhaven.
Afloat.ie will have more on this breaking story as it emerges.
Update 1.18pm: RTÉ News is now reporting that all 30 people on board the Astrid have been rescued from the vessel, which is taking on water amid strong winds.
Update 6.15pm: The latest news from Oysterhaven is that the tall ship Astrid has sunk, and RTÉ News has photos and video from the scene. Is is still unclear how the Dutch training vessel came to hit rocks and take on water.
Update 6.20pm: Karl Grabe has posted the above video showing the capsized Astrid being overwhelmed by heavy seas.
Update 6.55pm: Afloat.ie has posted news of the RNLI's rescue of the Astrid's 30-strong crew in an operation involving four lifeboats - plus a statement on behalf of the sunken vessel.