Oh dear

I left the boat tied once at the front and sprung at the back using an old piece of spare rope attached to a 'nappy pin' and the back rope to a chain.

I returned to the boat to move it into Aston Marina for a month and found ...

the chain in two pieces on the back deck of the boat with the spare piece of rope in two parts.  The boat tied up securely once more via the back rope attached to a fairly bent 'nappy pin'.

(So the weakest link were the old rope - saving the nappy pin and a link on the chain - saving the back rope)

The boat moored in front of us had found my boat attached only by the front rope when they moored up so they very kindly found all the bits and were able to retie the boat for me.  As far as I can tell the rudder is okay but so far not given it a thorough check over and there are no obvious new dents down the side of the boat.  The only scenario we can come up with is someone drove their boat at some speed into the ropes themselves between the boat and the bank.

No note of apology from the perpetrators who must have skeddadled sharpish from the scene of their hit and run!