I don't think you can buy 'day insurance'....that is why most windsurfers that I know are part of W.Q. ...insurance is just one part of the benefits of being a member. [To be honest, I don't like high-speed sailing with those who are uninsured. Have had my face cut open in a minor collision before (still beautiful tho) and accidents do happen, especially at speed when there are many using the same speedstrip.]