Life on any of the ten light vessels on the south and east coasts of Ireland was tough. The vessels had no engine and had to be towed into position by one of the Irish Lights tenders when required. They were kept in position by an incredibly long chain and anchor and thus, when things went wrong, as with the Daunt lightship outside Cork harbour in 1896, they were completely at the mercy of the elements with no way of manouvering the boat to ride the waves. As such, the crew were on the receiving end of a buffeting more than others though they were sometimes regarded by ocean-going mariners as 'not real sailors,' doubtless by men who had never experienced the conditions for themselves.
In 1930, the ten light vessels, located over sandy ground where lighthouses could not be constructed were, in alphabetical order, Arklow, Barrels, Blackwater, Codling, Coningbeg, Daunt, Kish, Lucifer, Skulmartin and South Rock. The latter two, off the county Down coast, were in Northern Ireland, though the lightships, like the lighthouses, all came under the jurisdiction of Irish Lights.
There is an interesting list in the Irish Lights archive showing the home towns of all 139 lightkeepers on the books in 1930, the year that Denis McCallig joined:
The Skulmartin lightship, probably the late 1940s