There is a new bit of legislation which will help you. Lots of other people are annoyed about it but it will help you. It is called the Protection of Freedoms Act which was enacted on 1 October last year.
This is the act that says that private land charges are now enforceable against the registered keeper of the vehicle. Basically if you over stay in the supermarket car park, they can charge you for parking and enforce it in the cart court.
I would write to the neighbour and tell him to remove the boat within the next 24 hours failing which you reserve the right to either take him to court for an injunction to compel him to remove the trespass and ask the court to award costs against him, or to pursue him for a charge for leaving anything there, in the Small Claims Court.
Put a big heading on the letter which says “Parking charge Agreement, Immediate Attention Required”
Tell him that if he leaves the boat there or parks any car there once 24 hours have elapsed from when he gets the letter, he is agreeing to pay you a parking charge of £100 per day, payable within seven days from the date of parking or leaving anything there.
Tell him that if he does not pay within seven days from the date of parking or leaving anything there, he agrees to pay a further charge of £40 per day in addition to the £100, and that by leaving whatever it is there, he has agreed to that.
Tell him that this is enforceable under the Protection from Freedoms Act and you will have no hesitation whatsoever in taking him to the Small Claims Court.
Tell him that notwithstanding that this will be a small claims matter, tell him that by continuing to park or leave anything there, he agrees to pay your costs of enforcing the terms of this notice.
The final paragraph means that even though it is small claims court, you can still claim legal costs!
Finish by saying that if he does not understand the significance of this notice, he should take independent legal advice.
If he doesn’t move it, send him an invoice for £100 per day and Sue him in the Small Claims Court.
Alternatively, if you don’t want to have the “fun” of all the foregoing simply apply to the County Court now for an injunction to compel him to remove the obstruction. Use court form N 16a
Does that answer the question? Can I help any further? Can I answer any specific points?
If you have not done already, please don't forget to positively rate my answer service even if it was not what you wanted to hear. You should now see a series of buttons which enable you to rate my answer service formally. If you don't rate it positively, then the site keep your deposit and I get 0 for my time. It is imperative that you give my answer a positive rating. It doesn’t give me, “a pat on the head”, “good boy” (like ebay), it is my livelihood! If in ratings you feel that you expected more or it only helped a little, please ask. The thread does remain open for me to answer follow-up questions after rating my answer service.