Kazz, I'm not sure about dogs in the swimming pool - you'd need to speak to Carol or Trevor about that. You can drive to the sea in 10-15 minutes though if that helps.
Regarding the garden, I didn't feel the garden with the house we stayed in was secure enough to leave the dogs in unattended. It was fine for a few minutes while we were in the house etc., but I wouldn't have gone out and left them with access to the garden. There's another house there, Swallow something or other, I didn't see all of it. A number of people from G/Gap have been there - with greys and lurchers - you could check with them too. I do worry a lot
I did absolutely love it there and would certainly recommend it. Carol and Trevor are lovely and made us feel VERY welcome - and it was a great place to go with dogs.