That other (ex) local would be me.
I'm biased but I think the bouldering is excellent. It's poorly documented, a little fickle conditionswise and often tidal so finding a local to show you the areas is the best bet. Failing that, the areas worth checking out are:
Peel: Limited DWS 'bouldering' around the back of the castle - weird but fun on a nice calm evening
http://www.ukclimbing.com/images/dbpage.html?id=69468Peel: Good, steep wave polished sandstone on the beach ~300m north of the skatepark on the promenade. There's good areas in the cave and on the beach but the pebbles rise and fall with storms, usually this time of year it's good. This is my favorite area.
http://www.ukclimbing.com/images/dbpage.html?id=71524Laxey: ~300m South of the promenade there's a nice cluster of boulders, Nik has documented these and there's a topo available somewhere on this site (not sure where, I don't use the site much).
Douglas, Marine Drive: There's a dead end road heading south down the coast from Douglas. On the beach below it (you'll have to park up and walk where the road is closed) is a wrecked boat, on the beach ~300m north of the wreck is some good bouldering. It's tidal but dries ok in a breeze. Approach carefully down the steep scree.
Chasms beach: This one is a little hard to find. From Cregneash, walk down toward the old chasms cafe then turn right and follow the coastal path about 500m until it opens out into a patch of bracken on the left. Battle through that then pick your way carefully down the slabs to the sea. Theres a couple of isolated boulders and a huge wave of steep slate
http://www.ukclimbing.com/images/dbpage.html?id=86593Santon: Park at Port Grenaugh on the east coast (between Douglas and the airport) and follow the coastal path ~1km until you get to a small bridge over a stream, there's a grassy rake on your right leading down to an isolated boulder and a wrecked marine engine. There's also a hidden gully full of short routes with bouldery starts just a few meters to the south. Tidal and fickle but worth a look if you fancy a walk.
Bradda: There's a good area on the beach behind Bradda (Port Erin) but it requires seasonal cleaning and I've no idea if it's been done this year. There's also a load of possibilities for further development lurking in the caves below this headland but the approaches are complex and frightening.
Scarlett: A little limestone wall near Castletown, maybe not worth a visit purely for bouldering but a nice place for a wander. The wall is directly below the visitor's center
http://www.ukclimbing.com/images/dbpage.html?id=86591You'll want a pad at all the venues listed and I'd say it's worth taking one with you. I'll PM the phone no of a local who's always enthusiastic, if he's about I'm sure he'd love to show the place off. If you're into trad too then I'd definitely get in touch with Doug, some of the routes are cool but they're as yet undocumented.
