I did my first sea dunking from RAF Bridlington in 1969 while I was stationed at RAF Topcliffe. We dry winch trained at Leconfield (I think) and were then bussed off to Bridders. Out in the very smart ASR launch and thrown into the oggin about a mile out. Each time we managed to scramble into our dinghies they came past at speed and capsized us. After about an hour and sick as parrots we were winched up by a Whirlwind flown by an AAC Capt on secondment, lucky blighter. Can't remember anything about the shore base I'm afraid.