Personal Flotation Devices
How to Properly Put on a PFD
In adults, the chest size determines what size is right. For children, weight should determine the PFD size.
Sizes vary by PFD brand and model and depending on the event you, your PFD options may supplied and therefore limited. A PFD should be snug and fit like a glove, yet allow you to move freely and not chafe while paddling and playing.
PFDs have different designs and foam placement to fit the contours of the body. Foam placement has more to do with comfort than safety. The more straps a PFD has, the more adjustments can be made to customize its fit.
Fitting: Once you've selected a size, follow these fitting steps:
Loosen all the straps, put the PFD on and if applicable, zip it up
Start at the waist and tighten all the straps. If it has shoulder straps, tighten them last. It should feel snug but not uncomfortable.
Next, have someone pull up on the PFD shoulders. If it moves up past your nose or head, tighten the straps. For children, neither the nose or ears should slip through. If it still moves up, the PFD is too large.
Check your movements to make sure it is comfortable and will not chafe you while performing your activity.
If possible, test your PFD in a pool or shallow water to see how it works. It should not ride up or slip over your chin while floating.
Sources
http://www.rei.com/learn/expert-advice/personal-flotation-device.html
http://www.rei.com/learn/expert-advice/kids-personal-flotation-device.html#