Bright idea for charity.
Eimear Browne, from Co Wexford, expects her trip to take her up to 10 weeks by bicycle.
The former lobster fisherwoman came up with the idea after her cousin Lee Cromwell died after battling for two weeks to survive at Beaumont Hospital following a car crash.
Eimear, who works for Irish Ferries, hopes to raise more than E30,000 for the Richmond Intensive Care Unit as a thank you for their kindness.
She said: "It's the only way I could think of thanking them for their wonderful kindness and work."
Eimear is even hiring boats to reach the 42 lighthouses which lie offshore.