If you have ever been caught in a sudden squall and have your aluminum boat get swamped (as I have) you will find that it is a terrifying experience. I grew up in the water, and am a surfer, and am not afraid of water in any way, but it was still terrifying.
This happened on a lake, under sunny blue skies. Suddenly, the wind started howling, and we headed back immediately. As we neared the shore, the waves bouncing off the seawalls made for a confused sea, maybe 4' high, and VERY close together. One, two three, and we were underwater. Just like that.
It happens so fast that it's hard to describe, but three quick waves, and the boat was down. Fortunately, there was enough foam in the boat that the nose of it stayed up, and we lost all gear, but were able to retrieve the boat. We survived that crazy washing machine, but it was scary.
My recommendation to EVERYONE, is that if you can, stuff every dead-air space you can with pink or blue foam. It's cheap, light and may save your life, especially if the water is colder than 60 degrees.
I've even seen guys put a bunch of milk jugs and soda bottles in dead space, duct taped together. Whatever!
But either way, if you haven't already, stop whining, and being cheap, and add some potentially life-saving flotation to your boat! Anyone's life is worth that much. How much would you spend for a doctor's visit for something not even life-threatening? I'm sure some floatation would cost only a fraction of that.