Unlike humans, dogs instinctively know how to swim and most are very good at it. However, our canine friends can’t tread water forever. If your dog falls overboard and becomes separated from the boat, he or she will eventually tire and could drown. A doggie life jacket can help. They not only keep the dog afloat, but function well as retrieving devices. Each has a handle on the top (see photo at right) that you can use to snatch your critter with a boat hook and then grab and lift the dog into the boat. …