Regular boats to Ireland's Eye run April-September from Howth harbour, €20 return. Small uninhabited island with 6th century monastery ruins, massive seabird colonies, surprisingly clear water for snorkelling.

Water visibility 3-5m calm days, lots of wrasse around rocks. Temperature peaks 15-16°C August - full wetsuit essential. No facilities so bring water and food.

Weather dependent so have backup plans. For snorkelling: east side of island more sheltered, avoid rough areas near seal colonies.