Looks pretty sound
I've checked the details over a number of times and couldn't see anything glaringly obvious, but it's always good to get a second opinion.
Right...take 2:
I've altered the stern to make it slightly less ugly and added various details, including searchlights, additional hatches, an extra capstan and ventilation points. Yes, it is still somewhat blocky, but I suppose that just reflects my approach to ship construction and it will be hard to change without totally reworking the design.
The rigging remains rather minimal as the lack of a mainmast makes it hard to follow most contemporary arrangements (e.g. South Carolina's), something I will bear in mind when working on future designs!!!