Been looking over the links (thanks peasemold) as we'd been thinking of filling in between sea trips with more river use in 2010. Seems near Peterborough we are in the most expensive area to register a 3.2m inflatable with a 10hp.
However for your use Jason it looks like a licence with no outboard is just £21-53 and an aux outboard of under 4hp is a nil cost extra.
That would save £200 a year over the charge I see with a 10hp... enough to get something just for the river like the mint 3.5hp Suzuki I sold earlier this year for around £150.
Hmm... perhaps I should have kept it... but there is always the Seagull in the shed!
If any of you guys are visiting the Central-West Canada, look me up. I'm sure we'll be able to find a lake or river to go boating on. I'll look after all of the water access fees, you cover the gas.