Cruise vessels were moored up during the covid period. Some moored here in Dover for short periods. They would not be able to moor in working harbours now of course.

Here’s what's happened to the cruise ships anchored in the Firth of Forth

Cruising is Out, But Enthusiasts Can Still Visit Laid-Up Cruise Ships

There will still be costs as they cannot be avoided no matter how the situation is dealt with.