I am also in reciept of Benefits at the moment and live in a 1 bed Flat, i did look into how it would work.
Here is what i found.
Under Housing Benefits Rules
1 you can claim for Mooring Fees
2 you can claim for Boat Licence
3 You can claim for Council Tax
4 you can claim for a Boat Safety Cert
I am not sure if you can claim for insurance though.
If you rely on NHS Services and Support on a day to day basis then i would say get yourself into a Residential Mooring if you can.
I will be claiming for council tax but none of the others, my dad is giving me a 1 year head start on the canals.
Dont give up your Health Support, i wish you well.