Fred - how much were they??
I know it is easy to say, but if you do a lot of fishing, you would do yourself a favour by having some swimming lessons. I used to be a lifeguard, and we had many "older" people come in for lessons. I was often surprised at how quickly many of them took to it.
Its not about swimming long distances, but having some confidence in the water so that you can "align" yourself in those important first seconds. For example, how to tread water would be a real asset, and you do not need to know how to swim to do it.
Also, I seem to remember some horror stories about either inappropriate vests or them not being worn properly. With all his pike fishing from boats Gary is probably better at advising on that one.
Good luck!!