It got a little bit better in the afternoon. I drove to the Bellstone, on the west of the island, from where a trail led to Great Stone Top. The skies were dark grey but it didn't rain. I parked up near the Bellstone, a small lump of rock which clangs satisfyingly when you hit it with another rock, and then set off downhill towards Great Stone Top.
The path was easy to miss at times. I didn't spot the branch leading around the side of Little Stone Top, so I climbed that thinking the path went over the top of it. Looking back, I saw where I should have gone so headed back down and around.
Eventually I reached Great Stone Top. I didn't go all the way to its highest point - that was across a vertiginously narrow ridge with a huge drop directly into the ocean, and in strong winds, I didn't entirely fancy it. So I stopped a little short and enjoyed the views back towards Little Stone Top.