Insurance for your boat is a legal requirement. You can find a list of narrowboat insurers on the site. Please note that your intention to live on your narrowboat and the age of the boat will have an impact on the insurance cost so must be declared.
The legal age to buy alcohol in Ireland is 18. You must be able to prove your age. A passport, National Identity Card, Garda SÃ­ochÃ¡na Age Card (Age Card issued by Irish Police), drivers licence are all usually acceptable. Expect staff to check your ID, particularly if you look to be in your late teens or twenties.
1 Previously young people over the age of 16 could purchase and consume alcohol <15% ABV, and adults aged 18 and over could purchase alcohol over 15% ABV.  As of March 2015, the autonomous community of Asturias raised its drinking age from 16 to 18 years. Asturias was Spain's last community with a drinking age of 16 years. The new law brings the drinking age into line with the rest of Spain.