Actually there are/were two Corsairs in Lough Foyle. One off Eglinton, but it was on the far side of a deepish channel so impossible to walk out to. I don't know its identity, but I think it was this one that the Navy rescued in the 1970s, with pictures of the engine hanging from a helicopter. No doubt the rescue ended there and I suspect the rescued bits were scrapped.
Just off Ballykelly JT693 was to be found. It was easy to walk out to it. I saw both around 1966 and I'll attempt to attach photos. If no photos with this post please PM me and I'll Email them to anyone interested.
Feroxeng