I don't keep my boat on L Derg, but I investigated having it there a while ago. Moorings are very difficult to get and I would think only be available through one of the yacht clubs. There is a private marina at Dromineer which I was told would cost about €1500 pa, cheap by E coast standards, if there are any vacancies - they have lots of space for out of water storage. Launching and retrieval is easy, as most places have a free public slip. However, you can only moor at the various harbours for 3 days at a time. L Derg yacht club has a waiting list for moorings as far as I know but they have lots of space behind the clubhouse so you could possibly launch and retrieve each time. I hope this is some help
Andy Sleeman
P235 Galatea