Just found out about these sites:
Home : Irishmariners.ie - an index of Irish merchant seamen active 1918-1921
Morwyr Cymru - Welsh Mariners
Indexes of Irish mariners (merchant seamen) from 1918 to 1921 and two Welsh indexes - merchant seamen 1800-1945 and Royal Navy 1795 to 1815.
Home : Irishmariners.ie - an index of Irish merchant seamen active 1918-1921
Morwyr Cymru - Welsh Mariners
Indexes of Irish mariners (merchant seamen) from 1918 to 1921 and two Welsh indexes - merchant seamen 1800-1945 and Royal Navy 1795 to 1815.