Thanks again for all your replies chaps, it is very much appreciated.
I think i am going to have to give the bath option a miss due to two reasons... I live in communual accomodation, so i dont think it would go down too well with my collegues!! and second the boat has been built as a static model not for water... and knowing my luck it would just sink anyway!!
After a great deal of trial and error, and who knows how many yards of masking tape, i think i have managed to get a line around the hull which from a yard or so away to the eye looks ok. With a tape measure the distance to the water line from the deck is different on each side, however only by a few mm, so unless looking in detail close up its not that visible. It was quite late by the time i finished last night, so ill come back to it later today and double check it.
It would appear that something went astray whilst building the hull, thus making it ever so slightly out of symetry.
Thanks for all your comments
Best Rgds
Aidi