Service in the Royal Marines means that at sometime in your career you will wear a lifejacket and in a variety of situations. The frequency and familiarity with this piece of equipment has allowed me to identify times on the water where in fact a life jacket is a far more appropriate piece of safety equipment.
I found a rather useful PDF where the UK Scout movement explain the CE and ISO standards relating to life jackets and boyancy aids.
water Safety The later half of the document relates to Scout association rules for choice of flotation wear.
So in this document you will see the following definition of a 50N PFD
Level 50 Buoyancy Aid
CE 50 Newton (11lbs buoyancy)
EN393 ISO 12402-5
Only suitable for competent swimmers.
Recommended for use in sheltered water where
help is close at hand.
Only provides support to conscious people who
can help themselves.
Inferior in performance to life jackets or the
previous BMIF Standard for Buoyancy aids.
This protection is quite limited, anyone who has swum ashore through 2mt surf will remember how uncomfortable that experience is.
This clip illustrates quite clearly how difficult it can be with even a small amount of chop.
There are different types of lifejacket, crucially an Automatic inflation is not appropriate. You must have control and choose when to inflate, that means choosing a manual inflation jacket. This post does not advocate an either or approach, but is simply to highlight the benefits of having a range of equipment that you can select from appropriate to your intended trip.
To make an informed choice, carry out your own research there are always pros and cons, consider these carefully, best of all try them out, and practise all your safety drills. Some you will find easier with the reduced bulk of a lifejacket, however you will loose the thermal protection offered by a PFD
Here is a rather excellent Hybrid PFD which appears to incorporate the best of both.
My choice is a 150 N Manual Life jacket with integral sprayhood, harness and crotch strap, using a crotch strap means wearing it under the spraydeck loosing the advantages of a double waist cag ….. just another thing to consider.