I've stayed with these guys when working on Angelsey....plenty fo room for a boat and the owner is a Diver (ex Commercial).....Beautiful house, very warm welcome, very secure for RIB, very good rates, and the smokery food is great too!....I will def use again (I've stayed in quite a few places up there.....)
Best Smoked Fish and Meat from Derimon Smokery, Wales - Location
Sorry, link is for the smokery itself, but is same place.....think its had good reviews on trip advisor too IIRC.
Its v close to Dulas boats if you should need any bits /pieces.....very helpful guys! Also, short drive to Moelfre where you can get a decent pint /bite to eat and nice walk.....Moelfre Lifeboat station also worth a visit......
Also, as others have said, if staying mainland.....Chris Ty Calch is a great guy and also highkly reccomended
Mention that Dan from Razorbill recommended if you contact them (working for Env Agency when up there)....might mean I get an extras sausage for breakfast (their own smoked ones incidentally