Hi Gareth
I have sailed on Lough Derg a couple of times, albeit around 20 years ago, there used to be a company hiring out Hunter 23 yachts. At that time there was quite a bit of sailing as well as motor boats coming up/down River Shannon. We had some really good sailing and I imagine it would be perfect for BR's . It can get breezy but being landlocked it's not tidal. On the first trip I spent 5 days sailing there and didn't get bored.
You could probably launch at Dromineer, which is on the east side. The West is more rural and scenic. There are quite a number of small "ports", a few with marinas, but quite a few which are just small quays. (Garrykennedy and Mountshannon are very nice.) There are shops/pubs in quite a few of the villages and quieter spots if you want. Being Ireland, it can get damp, but I don't actually remember any midges
From experience it's quite easily accessible from Dublin ferry port, 125 miles 2-3 hours drive, it's a bit further to Rosslare and roads are not as quick. (Cork is actually closest, but I have not driven that route. )
On my second trip, went on 3rd weekend of August and found it very pleasantly quiet as Irish school holidays are earlier than England/Wales. Would definitely recommend.
Richard Cooper
Storm 17 Little Grebe.