Just guessing that this is to enable them to continue doing essential surgeries and other things on the hospital ships without fear of contamination from CV.
Quite possibly.
My opinion only: I think this is an excellent idea. Staff the clean ship with personnel who've tested negative for chinavirus. Patients with other medical needs who also test negative will have a clean place for surgery or treatment.
We know that this particular virus is more contagious than regular flu. In the last century tuberculosis was an extremely communicable threat. Tuberculosis patients were sent to specific hospitals set up only to treat tuberculosis infected patients in order to protect patients in normal hospitals.
Using the Mercy ship as a treatment/surgery center for non-wuflu patients seems a good step forward in protecting those folks who aren't infected. As time goes on we may discover that the model of separate hospitals for treatment of this one illness can eliminate more of its contagion threat. Hopefully these treatments discussed will be so effective we won't need to think past another few weeks. But if it turns into longer term this is a good test system.
Again, my opinion only. Worth less than 2 pennies in the medical world. But my husband is a mechanical-piping system designer for clean systems in hospitals and pharmaceutical facilities. It's a normal night's supper table discussion for us.