If, for example, I live in a busy area of some city where they charge for on road parking (for purposes of this question the residents have to pay for parking too) but my garden was large enough I would be able, without planning permission or charge (except the dropping of the Kerb) be able to put a driveway on my garden. The only exception to this as far as I know is listed properties.
So if you have a garden that has a canal at the end is there anything stopping you, if the garden is large enough, to create your own small mooring by digging out your garden and thus ensuring that the land under the boat is owned by you?
I guess this could be a separate thread but it is kinda relative, in a strange twisted way, to this thread (and it's not like this forum ever goes off topic either )
Edited for American spellchecker (cheers athy) and grammer that was ungood.