This is the cruise I want to go on, https://www.shiprocked.com
Just keep your hands clean as much as possible, I think you have more of a chance catching something locally like the Flu, last August my wife caught Salmonella poisoning we thinks got it from the river water behind our house, she spent a week in the hospital. Three years ago I caught legionaries disease, those were both life threatening. Buy the insurance and go enjoy yourself