PFD Buyers Guide for Kayaking
The most important things to look for in a kayaking PFD, aka "life jacket" are fit and comfort. BTW, PFD is short for Personal Flotation Device (not to be confused with a "pdf" which is a computer file type for pictures). Kayaker's, canoer's etc. use USCG Type III or V PFDs. The Type V PFD that some kayakers choose typically looks like a Type III PFD except it has a quick release webbing belt above the waist which can be used for towing kayaks and other rescues.
There's no way to generalize all the factors that go into finding a good fit, so we go into detail about that in our individual descriptions of each PFD we sell, and we stock a wide variety of Men's and Women's kayaking PFDs by Kokatat and Astral. Kayakers may be the most demanding of all PFD users, so over the past few decades it has been kayaking PFD's the have led the way to better fitting PFD's. First Lotus Designs (now Astral) then Kokatat built modern kayaking life jackets made of more durable materials with more pockets, lash tabs for knives, and other safety features. These features also make kayaking PFDs popular for canoeing, rafting, and sailing. PFD's for kayaking need to be short so your sprayskirt won't push them up when sitting. Unfortunately as PFD's get shorter, they get thicker because you have to put the flotation somewhere. When taken to an extreme, this gives some of the river kayaking PFD's a thick "blocky" look and feel, but with a few exceptions, most PFD's designed for kayaking are also the best in terms of fit and comfort for canoeing, rafting, and sailing. Now that manufacturers offer women's life jackets, most women are better off with a women's specific model rather than a small men's PFD. Women generally have smaller diameter upper arms, so women's fit PFDs have smaller arm holes which helps prevent the jacket from floating up around your face when swimming. Some guys find they initially like the fit of women's PFDs, but due to the smaller arm holes on women's models, a guy is likely to get chaffing under the arms after a long day of paddling.
When trying on a PFD, first loosen up all the adjustment straps (typically there are two or three on each side, shoulder straps, and some have an adjustable belt below the zipper while others have chest straps on the front too), then put it on and snug up all the straps starting with the side adjustments. After getting a first impression about the feel of the PFD, have someone grab it by the shoulders and pull up firmly then let go. If it slips upward more than an inch, it's not a good fit and will be unpleasant to swim with. However, some body types may have to accept this (i.e. pear shapes would need a crotch strap to keep the PFD from slipping upward, but none of the kayaking PFD's come with a crotch strap).