Sounds like RFA Mounts Bay. She's been playing in the Eastern Solent and south of the Wight for the last few days. Perhaps they thought it was time that she ventured further afield. /forums/images/graemlins/laugh.gif
RFA sounds right for shape and size. I never seem to have my bins with me when I'm up Heng Head! There didn't seem to be any aviation connected with it but there were some little whizzabouts in the water nearby. I thought they might be looking for stuff to blow up and wondered if I should be prepared to have my windows ratteld again!