Background info:
https://www.tc.gc.ca/eng/marinesafety/d ... n-1324.htm

A life preserver (as far as I know) will keep your head out of the water even if you're unconscious. Not so a PFD.

EDIT: ah, there it is-

551.401 Life Saving Equipment Over Water - Life Preservers

(a) Introduction

This section contains standards of airworthiness for Life Preservers required by CAR 602.62.

(b) Definitions

In this section, a "life preserver" is a flotation device, which when properly worn by a person, will provide adequate buoyant force to support the body in a safe and stable position in water and provide a self-righting force to maintain the face above the water; (gilet de sauvetage).

A life preserver (as far as I know) will keep your head out of the water even if you're unconscious. Not so a PFD.

Correct. PFD's simply provide additional bouyancy, with no requirement to roll you face up. My understanding is also that an aviation approved lifejacket must be dual chamber, and have a water activated light, and whistle, though I know this from training, not 'cause I can pinpoint the requirement in a regulation.

On floats, I wear a non-certified boating Mustang PFD with the automatic activator removed. I have another one for my passenger . Both are very comforatable and do not interfere with movement in any way. There are 2 certified life jackets in the plane, but I doubt they will ever be used.

I would much rather have a PFD with no paper around my neck rather than a certified life jacket somewhere in the plane that I may not be able to reach.

YMMV
LF
.

I don't want to wade into the pros/cons or anything, but from a strictly logical point of view, if a passenger asks why you get the good vest and they don't, you can earnestly tell them that because they spend maybe one hour a year in floatplanes, and you spend several hundred hours a year in float planes, the odds are definitely in the passenger's favour, therefore the pilot deserves the good vest!