does any body know anything about legal contracts?

My ex and me splitt up a while ago. We both own a canal boat together. I've invested a lot of money into the boat and I would like him to buy me out. Which he would also like to do.

I want to draw up a legal contact that would stand up in a court of law to say that he owes me x amount and that the money he owes me will be exchanged for him to own the boat outright.

Any advice would be greatly appreciated.

Thanks.

England?
Do we assume that the boat is registered with the government, and that there is a title, much like for a car, with yearly fees and so on, and if so, who is on the title now?
Do we assume that these payments will be over a period, not all at once?
Once you know and have agreed on the amount owed, you can have one of two kinds of contracts:
One gives him ownership now, with a payment plan and a penalty if he doesn't pay, much like a mortgage on a house.
The other keeps ownership in both your names with a final date for turning over ownership after all payments are done.
Keep in mind taxes and fees are paid by the owner of record during all this.
Then you get your written terms stamped by a notary with witnesses present.
If he fails to pay you under the first type, I think you can put a lien on the boat. If not, you sue in small claims.
If you fail to turn over title when he's paid in full, he sues you.
The exact wording isn't what's important, it's that it covers everything, so if you aren't sure, pay someone.

... If he fails to pay you under the first type, I think you can put a lien on the boat. ...

If he fails to pay as agreed, OP should already retain an interest in the boat, or at least a lien.

The boat is registered with british waterways. Its in both of our names. Although when he applies for the licence next, he could easily just put it in his name.
Yes his planning to start paying me £50 a week once its back in the water (because its on dry land at the moment) he is doing work to it.

He says he can most prob get a loan in feb 2014. But he is not sure? So I no I need a time limit on this contract. But if I put a time limit on it he won't sign it.

He is also saying that when it goes back into the water he will use it as his home. So I'm only allowed acess when he is there. He has changed the locks.