Survey done today, few areas to work on, which seem reasonably straight forward and the chap carrying out the survey suggests we've nothing to worry about. Hull has lost at most 0.3mm from a 6mm start and been in water 10-11 years so bit of a confidence builder.
Does need some steel welding though, three holes almost in a straight line from the dump through tank which is obviously not a lined tank from the toilet. Seems a bit strange what has gone on there but with a new plate welded on should solve it for a few years to come.
Blacking started today, should be back in the water on Tuesday and then off we go!