The underlying problem, as I understand it, is the small but significant difference in US and UK laws.
What is not specifically prohibited in the US, is allowed.
What is not specifically allowed in the UK, is prohibited.
In this and many other respects, US law is similar to that of England and Scotland, from which it has evolved. In some other European countries what is not allowed is theoretically prohibited - hence the "Gallic shrug".
(N.B. The above is notwithstanding the mission statement of the UK CAA: "Everything is prohibited unless we've worked out a way to charge you for it.")
England difficult cos water is classed as private property and they have medieval trespass laws. Lake District National Park speed limited so impossible.
Scotland, much more free and easy. Best choice of landscape, water and FREEEEEEEDOM !
Trespass: in practice, most large landowners are not as easily upset as one might think. Even lairds who have never seen a banknote are unlikely to refuse a bottle of vieilles vignes from Bergères-les-Vertus (part of every Maule driver's MEL).
LDNP: wording of byelaws varies from lake to lake, so worth checking the small print. Speed limits are actual ground/water speed (not TAS), which a prosecutor would need to establish with accuracy beyond reasonable doubt.
Scotland: plenty of water here, but the weather is always crap. Don't be taken in by this video which was obviously made on FSX: