What’s the strangest reasons ships sit out at sea?

Any Mariners out there with any strange stories or explanations as to why ships just sit out at sea!?

I arrived in Falmouth, r/Cornwall a few days ago for a family holiday & these great ships have been sat out in the bay and haven’t moved since. It got me curious about the strangest reasons, other than the obvious, why this might be?

I understand lack of port space, waiting for clearance, commodities price speculation, crew changeover ect but I’m after the odd and strangest reasons!?