This question is about the Princess cruise ship that was sailing in circles off the coast of San Franciso.
Why not bring them into an isolated port (as they did), remove the medically necessary (as they did), fly non-Americans back to their countries (as they did), and leave the rest on the ship for 14 days of quarantine? How is being quarantined on a ship any worse than being quarantined on some military base? They could bring the ship whatever supplies they needed and avoid the risk of spreading the virus by moving people around in buses through a large metropolitan area? They could also refuel the ship and send it back out into the Pacific Ocean for two weeks. It’s not like anybody is going to want to cruise on that ship for a very long time.
Simply put, a cruise ship is a pretty bad place to try to control a contagion. This Wired article (paywalled) outlines the reasons the infection rate kept climbing aboard the Diamond Princess in Japan last month.
If your goal is to limit/control the number of cases, you’re better off doing the quarantine at an on-shore facility: more space between subjects, less reliance on closed-loop air conditioning, ability to separate the sick from the healthy, better control of the quarantine measures in general.
The Diamond Princess has a length of 290 m and beam of 37, 13 decks and a capacity of ~2600 people. So lets assume a length of 250m, a width of 30, 10 decks and 75% effective space. Total “floor” space works out to 56,250m[sup]2[/sup]
So assume 2600 passengers and a crew of 1000 and you have 15.625[sup]2[/sup] per person. That’s roughly a 12’x12’ square.
AIUI, on the Diamond Princess, the crew was making and distributing meals during the quarantine. Yet they hadn’t gotten any training in procedures for that. So that was likely a major reason the virus kept spreading. And on the Grand Princess, most of the initial 21 cases were among crew.
And, if it’s like the underpaid, overworked crew on most cruise ships, they have no paid sick leave. They are required to report for work even if they are sick, or lose out on their pay. So this encourages crew members to show up for work, to prepare & serve food, even if they are sick. A wonderful way to spread contagion thru a population.