How can I pay for my Boat

There are several options that I am investigating.

Marine Mortgage

As this is only the inital stages of the investigation I am not fully aware. It would appear that these have a limit of 15 years.
They appear to have a limit of something like 80% of the value.
Interest rates are a bit high - 8.2% APR or so...

Unsecured Loan

Take out an unsecured loan, but these tend to be a maximum of 60 months.
Tend to be limited to £25,000

Extend the house mortgage

Extend the house mortgage so you have another 25 years to pay for the boat.

Using a boat as a Pension fund

This needs investigation but under the UK pension rules that you can invest in just about anything I wonder if a boat could be a pension fund? And what the benefits are.