Funniest ('cos it wasn't risky) rescue I ever heard was on the Erne system. Bloke got lost at dusk - couldn't find Lusty Beg. I swear to God I hurt something important from laughing listening to the comms...
Get the "map" thingy or whatever it is you freshwater rats have..
For your charts of Lough Erne (or are they maps), go to the large blue glass waterways building opposite Broadmeadow in Enniskillen. They produce some good guides and charts. The islands can be confusing, but you soon find your way around, after the 2nd day I knew the Lower Lough quite well. You have to visit Lusty Beg, it's beautiful. The marking stakes take about 30 seconds to get used to. Round post split vertically into a red side and a white side. Remember in the red your dead, in the white you are alright, (bit drastic I know), but it can get very shallow in the red area's. There's a 5 knot speed limit sign and when you exit the restriction (a National Speed Limit Sign-like on the roads), and that's it.....Easy! See the National speed limit sign on the photo when you enlarge it!
Soulman - if your new to boating I would recommend Upper Lough Erne. Lots of public slips and all free (Carry Bridge, Corridillar, etc, etc). The upper lough is much more sheltered as there are plenty of islands to keep chop down compared to lower lough.
If your new to launching etc might be best to try and go mid week as public slips can be busy at weekends. Mid week you will have them to yourself and you can take your time launching and recovering.
Get a the latest OSNI activity map (2008) for navigation on lough erne. It has both upper and lower (one each side) and is printed on water proof paper. ISBN 978-1-905306-26-8 under a tenner from a book shop.