Hi Richard, it’s a tricky subject and really depends on whether moving your boat is essential travel.
I would ask the RYA’s legal contact for advice as your situation is a little different to ours. They’ve always been very helpful to us in the past.
We live aboard FT and our N42 is our one and only home, though this confuses many given how nice Nauticats are…still significantly less expensive than a central London flat.
To that end we’ve been told that we can’t be compelled to stay in a marina paying fees and are on the hook in a river. As long as our travel is essential, e.g. getting food, exercise etc. then we’re ok to do so.
We did talk to the RYA and local marine police unit first before moving and I’d suggest that’s a better approach than having them chase you down. We always get names and contact details of who we talk to and jot them down in the log.
Our alternative could have been to sail across the north sea to NL which is where we’re flagged but given the weather recently in the N.sea and other factors we decided against.
Hope that helps, but as mentioned sounds like a quite different set of circumstances.