Staying on board
In the past, when having conversations with people about the benefits of martial arts training, I would often compare the activity to swimming. My comparison would be that one hopefully doesn’t train in the martial arts solely because they are afraid that bad guys are lurking behind every tree or in every alley, hiding in wait to pounce on unsuspecting victims. People train in the martial arts, or at least keep training beyond the very basic stages, because of the myriad of other physical and social benefits that come from the practice.
Swimming, in my opinion, is a lot like that. Learning to swim solely for the reason that you are afraid that you will fall out of a boat is pretty silly, for a variety of reasons. First, you will no doubt be engaged in pleasurable water activities way more than any life-saving variant. And more importantly, swimming skill may very well NOT save you if you do fall out of your boat!
MOB (man overboard) situations are super serious, especially for a short handed crew (like a husband and wife couple). Some safety can be added to the equation by wearing a PFD (personal flotation device or life jacket) but that is still dealing with the problem after it occurs. A better solution, and one which is used by many sailors in certain situations, is to wear a chest harness and be attached to the boat via a tether so that you can’t fall overboard!
There is some excellent info on the subject on a Blog that we regularly read: Sail Delmarva. Although Rebecca and I have yet to acquire harnesses, or the auto-inflating PFDs that we want which have harnesses integrated into them, they are on our boat-show shopping list.