In reply to jon59:
I was stationed there for 6 months with the RAF in 2003 and did quite a lot of new-routing with a guy called Mike Formby. Mike put together a digital guide which he left with the Mount Pleasant Gym - I suspect you may be referring to that, and although I share Andy Kirkpatrick's surname, we are not related! However I take it as flattery, as he is no doubt a far better climber than I! We concentrated on a cliff on Mount Challenger, 70m high in places and about 100m long. Loose rock in places, as expected, but some good climbing in a great location.We also put some routes up on Mount Pleasant, mostly short boulder-type problems, but one or two longer routes.
I agree that Vostock, on Mount Harriet, is a great route and well worth its 3 stars.
Another who put some new routes up there is Terry Moore (ex-RAFMRT) who was there a couple of years before I went.
I also spent time on Ascension Island and agree the rock is not conducive to climbing - the diving, though, is excellent.