In the meantime I had managed, by dint of much pushing, shoving, huffing and puffing
The C&RT chap explained that, as it is a long pound and it was well down, it would take several hours to bring it up but he then kindly checked the depth over the cill and said it was ok for us to transit the lock, bless him.
Having moored in town we had a wander around Castle Quays shopping centre (Ugh!). We are getting somewhat short of crockery, china ware has a tough life onboard, and although we found some we really liked they didn't have enough to meet our needs, looks like chipped plates for a while longer.
Watch this space.............