Hi lads thanks for the comments

I have got some ideas but Im not sure if I'm capable of doing what I would like to do. This is only the first layer of planks so I've used this layer to learn and practice as much as I can for the final layer.
I've got some nice pieces of boxwood, pear and mahogany and I would like to cut some planks from these and then use all three woods on the hull.
I'm thinking about using the light boxwood to mark out the water line and then use pear below this and mahogany above. Now this is what I would like to do but I've never done it before so I'm not sure how it will pan out or even if its possible for me personally to do. My thinking is that I'll give it a good go and if it doesn't look right I'll just paint the hull rather than using a clear coat to display the wood. I'm sure I'll need loads of help and advice but hey I know where to come for that
Martin - this technique of bending laterally works really well and I would recommend it to anyone to give it a go. Here's a bit of a better explanation of how its done.
Here is how the plank naturally wants to lie when placed on the hull. You can see that it runs away from the planks above at the stem. It can be forced into place but if you do this it will not sit flat on the bulkheads and cause clinkering.

So what I do is mark the beginning of where I want the bend to start and also mark roughly where the middle of the bend will be.

I then use these marks to clamp the plank to a board and put a bend in it just roughly to what I think it should be. I really need to make myself a decent jig for this but I've been to lazy so far to make one

Apply some heat - I use a heat gun simply because I've got one but I've also used my wife's hairdryer and that worked just as well

After its cooled try it for a fit on the hull and repeat as necessary until you get the desired bend. Here's the plank after a couple of goes on the hull and you can see how now it naturally lays up to the planks above

Then do the same towards the stern and you end up with a plank which looks something like this. The only other way to achieve this as far as I know would be to spile it which takes a lot longer and wastes a lot of timber too.

Then fit and glue it, and you get a nice plank like this one which follows the shape of the hull and is a tight fit on the plank above it. More importantly though is there are no built up stresses in the wood - its laying exactly the way it wants too.

I have to stress that this is not my idea; I've simply
robbed, stolen, pinched sorry borrowed someone else's expertise. Well why reinvent the wheel! Anyway I hope this helps someone.
Mark