Where did you find the textures?
The only thing I can see, and I don't whether you can do something about it, is the texture on the protrusions beneath the prow and bow (sorry, don't know the name). The texture should also be trapezoidal, no?
For sails, have you tried putting a bump map? Something like the canvas texture in Photoshop?
Otherwise, excellent modelling and texturing.

-- erlik