The
PFD Knife, Don't Leave Home Without ItNo doubt some experienced sea kayaker will argue there are many reasons why either you do not need a knife or it is OK to carry the knife in or on the kayak. It's what you can't predict that makes the best survival test. After each novel sea kayak death is analyzed we try to avoid a repeat performance. I opt to avoid being a test case.
In the analysis of a kite-sailing mishap that ended in the death of the kayaker, Sea Kayaker Magazine noted in their August 2001 issue, "If the wind builds while the kite is in the air, it may be very difficult - if not impossible - to reel in ... a tethered knife with a blunt point and edge serration should always be available..." Photo: Gerber River Shorty at REI
In April 2000, Sea Kayaker Magazine noted, "The Great White shark turned ... and it was now facing the kayak ... the shark was within an arm's reach, and its eye was looking right at me. I was two miles from shore, in a kayak ..."
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The Sydney Morning Herald notes, "Attacks on people are a result of mistaken identity or simple curiosity. A shark, with no hands, uses its mouth to investigate an object, often with dire consequences."
Would a knife help protect you against a 'curious' shark or a hungry crocodile? I don't know but I would like the option.
The most likely reason to immediately need a knife while kayaking is to cut rope or line. Tow lines gone wrong, heavy fishing line with heavy fish, sail or kite rig, paddle leashes, life lines and spectra rudder cables (unless you use stainless, in which case you had better have wire cutters with you).
Even a damaged composite or plastic hull will succumb to a knife with a serrated edge if you need to finish removing the nose or tail kayak 'dag'. How about breaking your boat in the surf and having bits of deck line, sail line, rudder spectra, and paddle leash with half a boat all in the same soup as you? Something can get wrapped around your leg, neck or body.
"Something went tragically wrong for an avid kayak fisherman (not a novice) He was found dead, upside-down and still seated in his kayak. He had been paddling a normal sea touring kayak with a typical large keyhole cockpit ... He was wearing a PFD ... his poles were still deployed ... A miniature carabineer was also found clipped to a line running from bow to stern ... the carabineer was attached to his PFD by a short line ... the investigators strongly indicate this arrangement was a significant contributory factor to his inability to wet exit ... a good survival knife should always be carried and accessible." So said Doug Lloyd in issue 40 of "NSW Sea Kayaker."
So,
having warmed your interest to the concept of securing a knife to your
PFD, what sort of knife should you consider? Firstly, does it matter
from what the blade and handle are constructed? Exposure to salt water
and prying open oysters is a sure-fire way to terminally test a knife
made of the wrong material. Most people would accept that 'stainless'
steel is a good idea for knife to be used in and around water. However,
all steels can rust. A very high carbon steel alloy that holds a great
edge and can be found on expensive hunting knives would be inappropriate
for a utility PFD knife.
Stainless steel with less than 0.5% carbon is very soft but is also very stain resistant (corrosion resistant). Often used for diving knives and inexpensive knives but too soft to be used as a useful utility knife. Clever (and more expensive) stainless alloys with more than 0.5% can provide an acceptable degree of hardness whilst maintaining useful corrosion resistance. However, increasing carbon content will trade off corrosion resistance, 0.65% to 0.75% seems to be about right for an acceptable utility knife with good 'stainless' properties. You will not find a good blade on a cheap knife.
The most basic choice in blade design is whether to chose a plain or serrated edge to the blade. As you would expect there are advantages and disadvantages to each with the debate akin to the rudder-equipped versus rudderless kayak. To simplify the discussion one can consider two cutting functions of a knife, push cuts and slicing cuts. Examples where a push cut is used are dicing a carrot, chopping wood; i.e. pushing the blade through the material. A plain edge is generally better for push cuts. A plain edge is also better for fine control.
Slicing cuts are performed by dragging the blade across the item to be cut. Dragging a knife across a tomato or sawing wood are examples. Serration works well on hard or tough surfaces where the serration tends to grab the surface. Some of the power of the serrated edge is due to the form alone; thus, even a dull serrated edge will perform slicing well. A plain edge needs to have a more razor-like finish to push cut well.
![]() Photos: Our PFD knives. Note: We have never had the chance to use our knives in an emergency situation but we do carry these knives clipped in our PFD pockets, fully knowing the extra steps it takes to deploy them. If we sailed, fished or ran rivers more often we would likely go for the River Shorty type knife. ![]() |
Sharpening
a plain blade is relatively easy but usually needs to be performed regularly.
A serrated edge requires attention a lot less frequently but requires
a special sharpening jig. To get the best of both worlds, or to compromise
the best of both, there are knives with a combination of plain and serrated
edges. Typically, the 50-60% of the blade nearest the tip is plain while
the back 40-50% is serrated. A blade length of 80 mm may only provide
30 mm of serrated edge which some consider borderline useful. Nevertheless,
a partially serrated blade of 75 mm would be the minimum to consider.
There are also double edge knives with a plain and serrated edge.
When it comes to cutting rope or sawing through damaged composite hulls
the serrated edge comes into its own. The Spyderco folding climbing knives
are serrated and cut 13 mm climbing rope like butter. My feeling is that
a PFD knife should be a least partially serrated.
The
next major consideration is whether to have a folding or fixed blade.
In my opinion a fixed blade is the only option for a PFD knife. The
folding knives are elegant, give you a knife with half the carry length
and don't require a separate sheath. The integral belt clip means that
the knife can be carried on the belt, PFD or boot with ease. However,
whilst many are designed to be opened with one hand, they are not ready
to go. You have to locate the knife, remove it from the PFD and deploy
it before you are ready to engage the enemy (be that spectra rudder
cables, paddle leash or crocodile). The pivot mechanism can be prone
to corrosion in even the best maintained knife which increases the risk
of a difficult opening.
A fixed blade is fail safe and is easy to clean and maintain. Many knives have sheaths, designed to be attached to the PFD, and one only has to locate the handle and pull the knife away. Generally, the handles are ergonomically better on the fixed blade knives and the cost should be less for the equivalent quality blade.
The handles
and sheath need to be some form of synthetic. Zytel, Kydex, ABS, Nylon
and Kraton appear to be common materials used. Kraton has a soft feel
that is said to be easy to grip with wet hands. Other materials are molded
in such a fashion as to provide good grip. Some knives on the market are
provided with a leather sheath and this limits their use for sea kayaking
, look for a synthetic sheath as well.
Various mechanisms are used to secure the knife into the sheath so that
it does not deploy inadvertently. They all seem effective enough. However,
once pulled out, deliberately or not, if the knife is dropped it will
be lost. The option of a lanyard bothers me. The lanyard may deploy the
knife by mistake in the first instance. A tethered and uncontrolled knife
during a roll or brisk brace does not appeal to me either. I simply attach
the knife to a small, hollow plastic float that the yachters use for their
car keys. This aids in locating the knife if upside down and disorientated.
The knife will float nearby if dropped rather than flapping about tethered
in front of your face.
The point of the knife comes down to personal preference. The 'clip point' is considered a good all-round shape and is what many people imagine when they think of a knifepoint. There are blunted styles, either rounded or chisel. This will give a strong tip that can be used for prying or scraping but less effective for stabbing / piercing type actions. A blunt point may decrease injury to equipment and yourself if you lose control of the knife. I personally like a point that can be used for stabbing, reserving the right to poke wayward sharks and crocs in the eye should the need arise. Most 'rescue' knives have some form of blunt tip.
In the end, personal preference for one feature or another will decide for you on which knife to carry. As long as you roughly choose from the above criteria it really doesn't matter what knife is on your PFD. A good quality knife is one of the most important survival tools you can carry. However, if you can't locate your knife when upside down with your eyes closed then it's no longer a survival tool, it's ballast.
Editor's
note: Remember to comply with laws pertaining to the carrying of edged
weapons in the areas you wish to paddle. Further information on knife
laws can be obtained from the Editor.
Use the Lash
Tab, that square looking thing on the shoulder of the PFD, found on many
life vests. Most river knives will easily attach to this. Dive Knives will
need to be lashed on and knives with a belt clip can be "clipped"
but there is some chance of them coming off.
IS CARRYING A KNIFE ALWAYS SAFE?
Care must always be taken when using such a sharp tool, both in emergency
situations and regular use. The story, paraphrased below illustrates
that while I knife can help it can also hurt. This incident was fatal.
"Michael R., an experienced kayaker, was navigating the river when
his boat overturned in a rapid on the Ocoee River. Friends told that
he lost his paddle and was unable to flip his boat upright. Once up
righted, the friends could not remove his Spray Skirt, so they cut it.
When they did, they also cut a main artery in his leg." Copyright
1997 The Associated Press, Monday, November 3, 1997. ©Copyright
The Oak Ridger
PFD Knives are available at R.E.I. (purchases using the banner link
at the top of this page help to fund this site)Type "kayak knife",
"Gerber River Shorty" or simply "knife" into the
REI search box to see a selection of knives.
Author: Although Trevor Gardner
is a veteran seakayaker with a club (NSW Sea Kayak Club) promoting exclusive
use of traditional, specifically outfitted closed cockpit boats, their
newsletter editor Richard McNeall was happy to offer this great study
on the subject of PFD knives to TopKayaker.Net, saying - "The more
interaction in the world kayaking community the better!"
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