A friend of mine was recently bumped from his carefully selected cabin pre-cruise because that entire floor/side was being reserved for covid positive travellers (presumably for people who developed covid once on the cruise). So it looks like the companies are taking precautions - FWIW I wouldn't go on a cruise at the moment because the Petri dish scenario is very unappealing.
However two other friends have recently completed continental river cruises but made no mention of any covid issues - lack of river depth was their concern.
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