Why are the ships moving around so much?

I've also heard that some lines are cruising to drop off their crew members in their home ports.

Expenses of one sort or another is still ongoing.

Port fees can be very expensive. It is one of the reasons that ships having a 3 hour sail between 2 ports will take a full 10 hours to do it. Many ports charge by the hour and I do not think there are enough births to seat all the ships at one time. Plus with no shore power the ships have to run engines constantly and the ports do not want all the extra pollution.

From what it sounds like, The ships a pulling into port, at a minimum of every 7 days, to take on provisions and fuel, and to discard garbage. They're obviously not taking on as much food as they would if they were chock full of passengers.

I've also heard they are navigating around to avoid rough seas and sheisty weather, for crew safety and fuel savings.

The thought occurs....mebbe they need to dump their processed waste at sea, or need to be at sea to take on salt water to be desalinated...mebbe they only need to dock to take on supplies...or or or????

I have no clue...never thought to do that...hmmm...rainy day here...seems to me moving them around aimlessly costs more than "stashing" them somewhere. When docked, they may or may not use shore power. I still think there are thousands upon thousands of crew still stuck aboard, and I believe most ports don't want anything to do with them. And I don't know theres any solution to that, OR getting most of them home to wherever. I'd love to read the answer to your query...