If the water was reasonably deep i suppose you could attach an anchor angel to the main anchor rope. Then run a line ashore - the catenery effect would pull it off the shore and then when you want to pull the boat in you just heave and the weight comes off the bottom and the boat comes towards you.
I've just had a reply from the Salcombe Harbour Master (part of our trip), so my original question wasn't quite as stupid as I thought - "Unfortunately the harbour byelaws do not allow boats to be left at anchor without someone staying on board" ! So I'm going to tie up and put out a stern anchor, ho hum ...
Thanks for all the help - I have as usual, learnt a lot from the forum.
