Mmmmph. BugzyCan: you may think you're joking, but they may be making a common error by fixating on just a
single risk, ignoring all the rest. Sometimes that's appropriate, but keeping an eye on the measures makes sense.
To reduce the basic reproduction number of a disease, you need to reduce contacts * susceptibility. To reduce contacts, social isolation works great! As for susceptibility, you need a healthy happy populace---people who are stressed, aren't exercising, aren't leaving the house, etc., are compromising their immune systems. For a few weeks the effect is dwarfed by the reduction in contact rate, but eventually it's important to consider the unintended risks of isolation, and figure out how to stay all-causes healthy.
Too much isolation and lack of exercise and fresh air means you're not just increasing your susceptibility to covid19---and I'd guess to worse complications thereof?---but to a host of other illnesses, chronic stress, mental illnesses of which depression is just the beginning, heart disease, relationship stress with cohabitants, possibly domestic violence, etc. (Irrelevant to sailing, but perhaps interesting from the unintended-consequences perspective: in various countries, especially in the third world and the
USA, the wealth gap is such that shutting down the economy is likely to throw a large proportion of the population into catastrophic poverty, and your chances of surviving that are worse than your chances of surviving covid19. I'm skeptical of anyone who claims to know exactly how to balance these two opposing risks.)
Sailing is one of the most socially distant ways to get some sunlight and exercise and relief from various forms of stress and pollution, and basically improve
health and reduce susceptibility.
As long as you don't come close to other people (e.g. don't need rescuing), and don't do anything that hurts people (e.g. run a
motor within earshot or noseshot of anyone), anyone who goes sailing probably improves public health.