While there are "unsinkable" boats, just because a boat is still floating doesn't mean it's of much use. For many, many boats in recreational use, the most common "capsizing" event isn't really a capsizing event. What usually happens is: 1) the boat takes a wave (or two over the stern) 2) The bilge pumps can't move it out fast enough and even with a self bailing boat, the owner didn't have the good sense to get on the throttle to help things out. 3) The boat, now sitting lower in the water takes a few more waves over the stern and soon the cockpit is full. 4) The boat turtles - e.g. turns over AKA "capsizes" (I distinguish this from a "true" capsizing in which the boat rolls over from a large wave taken on the side of the boat). 5) The foam floatation in the boat (and sometimes trapped air in the bow) prevents the boat from sinking. 6) The former passengers are now outside of their overturned boat and are trying to figure out how to access the life vests trapped inside/underneath and/or how to climb upon a slippery upside down hull to get out of the water. That "unsinkable" boat is not much help at this stage. Sometimes a bow line can be found a used to hoist one onto the boat. Sometimes people can get part way out of the water by standing on the upside down swim platform or engines.
Depending on sea state (height and frequency of waves), the time between that first big wave over the stern and the boat turning over can range from several minutes to 10's of s. It often happens that the first wave or two doesn't seem so bad and the occupants don't realize how quickly things can go bad from there. People often dick around trying to reel in lines, secure rods etc. when more immediate action (often throttle) is required to prevent subsequent waves from coming over. By the time they realize they are in deep, serious ****, they often don't have time to find much less don the PFD or to call the coast guard. My buddy rescued two people clinging to the back of an overturned Trophy in the Puget Sound a few years ago. They spent about 45mins in water that was around 47F and were close to succumbing to hypothermia by the time he pulled them out. The situation was very similar to what I describe above with the extra complication that the guy's boat had been broken into recently. The thieves had removed a round plate in the engine well while attempting to steal the motor. The owner hadn't gotten the boat fully repaired prior to taking it out (the VHF was also missing). He was trolling in winter (Jan I believe), took waves over the stern, spent time trying to get the gear in and the boat turtled. His wife got off a cell phone call and misreported their location as on the opposite side of the island they were near. She hit the water with a life vest on, he hit the water without.
So like others have said, wear that PFD at all times while on the water. Unexpected things can happen and happen fast. Just a single slip while trying to net a fish can put you into the water in a second. Self inflating PFD's are light and comfortable and can be worn without inhibiting your fishing at all. A handheld VHF in a floating case can be a life saver if you have it in a readily accessible location. There are small flares that can be put inside a pocket in most self inflating PFDs. I have one or two of
these small flares in each vest. There are really nice,
water activated strobe lights that will help you be seen in the dark. I have these on the PFD's also. Finally, for offshore,
PLB's are getting fairly inexpensive. I have two on the boat - one on my buddy's person and one in my ditch bag. The ditch bag contains a handheld waterproof VHF in a floating pouch, a handheld GPS and my PLB. At the start of each trip, I put the ditch bag in a well defined location close the helm.
