Good to see it's still a going concern.
I wonder what state the concrete caissons are in. Maybe the sea will reclaim Sealand in the end as it probably will not be easy or cheap to repair.
Presuming Sealand continues to be understood as outside the UK's jurisdiction, I imagine the right motivated investor could actually expand Sealand into a larger artificial body.
As long as it doesn't pose a danger to the UK and isn't distinctly criminal in nature, it's probably not going to get much attention.