What to do when someone is in your slip

[CruiseN]

I was old enough to have a boat licence, to young to drive a car, we had keel issues and needed wait until morning to fix.
Knowledge of local marina included vacant slips and I just didn't sleep well on a short rode in mud so me and my mate tied up in a slip.
Security was nice and told us no.
We anchored 100metres away instead out of channel, out of others way. (No room now because expansion)

We stayed on vessel though incase..

[Montanan]

UK law regarding trespassing of a vessel in a marina.

Trespass

The marina is able to bring a claim for trespass seeking an order for possession of the boat as well as payment of the outstanding fees. If the order for possession is granted by the court, the marina will need to instruct a bailiff to remove the boat. The bailiff is able to sell the boat if the owner does not pay the sum of the court judgment, and the proceeds of sale will be used to satisfy this. The marina is also able to seek an injunction against the boat and the boat owner to prevent them from being in or berthing in the marina, if such an injunction is necessary.

Harbours, Docks & Piers Clauses Act 1847

This Act applies to marinas that were created by special Acts of Parliament and are therefore usually commercial or fishing ports.

The marina can arrest or detain any boat that is berthed or stored in the marina in respect of which there are outstanding fees (known as “rates” under the Act). The boat can be detained until the fees are paid or, in the event that they are not paid, the marina can sell the boat. The marina is entitled to do so without the need for authorisation from the court. The action is taken against the boat and not the owner so it does not matter if the current location of the owner is not known by the marina.

To exercise the power, the marina must make a formal demand for the outstanding fees. If they remain unpaid, the marina can then arrest the boat by serving a notice that it has been seized in accordance with the Act. The notice is served by placing it on the boat. The notice should also be sent to the owner (if the marina knows where they are). If the fees are not paid within 7 days of serving the notice of arrest, the marina can have the boat valued by two independent valuers and then promptly sold. The proceeds of sale will be used to pay the outstanding fees and the marina will have to account to the owner for the balance.