Oh, I see, well I'd be happy to pay a higher licence fee to more accurately pay for my boating, I was more thinking about my monthly donation as somewhat paying for my general enjoyment and use of CRT infrastructure in the same way I support the RSPB, wildlife trusts & National Trust.
One other thing I've been thinking about is the Trust building an "end of life" fund (for boats, not boaters). There are quite a lot of notifications about sunken / abandoned / "terminal" non licensed/ insured/BSS boats and they can be pretty expensive to deal with in difficult locations.
I see that the total annual cost is estimated at substantial. My idea is a small first registration charge to reflect the theoretical end of life cost of a boat based on recovery / removal costs and % likelihood. Over time, a fund would build up to deal with these costs - and the additional cost for a new narrowboat would be inconsequential.