Sea state forecasting and reporting sources

Passageweather.com Magicseaweed.com Metoffice.gov.uk Met.ie Nci.org.uk (phone and ask) Around Ireland, and in addition to the standard met buoys, seven navigational buoys measure conditions including sea state, and tweet the data every 20 minutes. See cil.ie.

This swell forecast indicates 18m off the northwest coast of Scotland