Dive Knife

[downunderhunter]

I would be worried about the sheath retention on the moras. All that I've owned (30+) have been very poor. Overcome that, and they would be most excellent for a sharp cheap requirement.

 

[Double_J]

The sheath retention would have to be pretty solid, along with having an easy way to strap it to my body/gear.

 

[Willie Sutton]

The Moras are actually a favorite of many divers. Dexter is another similar brand that we like.

I wear one and have done so for decades (literally) without any retention added at all, *except* on a specialized freediving weight vest that I will describe a bit later below. The knives do not tend to fall out of the sheath, and in fact I've never lost one. I have had them mounted on my dive light for years, just taped on with electrical tape, and find that placement to be optimal for many types of diving as it's one of the easiest places to reach when needed. Fumbling elsewhere is difficult. At this moment I have one sewn to the side of a small nylon utility pocket that sits on the waist strap of my rebreather, offset just to the left of my waist buckle. I just seared a few small holes thru the nylon sheath with a small nail I heated with a torch and sewed it on. I've never lost one.

On my freediving weight vest, I do retain it as follows. First, the vest: For freediving spearfishing I took an old plastic tank backpack and harness and modified it into a weight vest by drilling a hole in the top of the plastic backpack and then filling the interior with lead shot. A bit of epoxy to plug the hole and I have a 10 pound center-back weight with a harness attached. I add a few more pounds to the waist strap and it's a beautiful thing. I sewed a Mora sheath as described above to my left shoulder strap. I then drilled a small hole thru the handle of the knife right below the butt, and passed a length of bungee cord (about 3/16 diameter) thru the hole and knotted it to make what looks like a wrist lanyard. When the knife slips down into the sheath, I then pull the loop of bungee down and slip it back behind the about one inch of sheath tip that's below the spot where it's been sewn on both sides to the webbing. The bungee isn't tight, it's just sort of the right length. I leave about a three inch tail on the ends of the bungee where it's knotted dangling down below the tip of the sheath. To retrieve the knife, I grab those and pull down, freeing the bungee from the bottom of the sheath, and then pull the knife up out of the sheath. It's VERY fast (bearing in mind that if I get snagged in mono while breath holding at 20 to 40 feet, I have SECONDS at most to free myself). I can then loop the bungee around my wrist as I work with a fish to pith it after shooting it with a speargun.

Now: The only reason I wanted retention for freediving (as compared to my scuba setup where I do not retain it) is due to that fact that I am often swimming thru the surf line to my spearfishing spots and then am being blasted by the surf back onto the rocks to get out of the water (Rhode Island is where I spearfish and it's not sandy), and because when I freedive I am absolutely heads-down while descending and I feared the knife falling out of the sheath after being partially dislodged during a surf entry.

This system has been foolproof for the 20+ years I have been using it. I actually have my spearfishing gear with me and tomorrow I'll try to take a photo. It's easier to do than to describe.

The Mora (and Dexter) knives are excellent as a good sharp cheap knife. They have enough carbon that they do rust a bit, and are pretty soft so they do not hold and edge for very long, but they are very easy to sharpen. I just keep mine razor sharp with a stone and replace them every now and then. I buy them by the dozen at a commercial fishing place in Wakefield RI and often give them out to other divers as gifts. I've probably given away a hundred of them over the years as I mentor divers.



This is the model I carry spearfishing, as although for other uses I prefer a blunted tip, when spearfishing I do want to be able to pith a large fish before putting it on my stringer. I normally buy pointed knives and just hit them on a grinder to knock off the sharpest point before use.


http://www.moraofsweden.se/morakniv/companion-f-serrated-50.0.200.2?group=prod_prod_grp-s1/41


This is another that I buy more or less interchangably with the above one:

http://newenglandmarine.com/products-page/browse-by/mora-frost-546-knife/


I've bought a few of these, as they have a snap-lock clip that locks securely onto webbing. They are specifically designed to clip onto the shoulder strap of the bib of a set of foul weather gear pants, worn on deck all the time by commercial fishermen. The lock is too narrow to lock onto the 2 inch wide weight belt type webbing but does work on many other webbings on divers gear. They are absolutely ubiquitous with commercial fishermen. Being dragged overboard by a pot-line around your ankle, you need INSTANT access to a sharp knife, in addition to the 100 other uses aboard a boat. Note the MAGNETS in the sheath that hold it securely. These are great and at a whopping price of $18.75, buy four.

http://newenglandmarine.com/products-page/browse-by/gage-knife-with-sheath/


These are also commonly seen, and at under $8.00....

http://newenglandmarine.com/products-page/browse-by/3-14-net-knife-wsheath/


But THIS is the absolutely most common knife we carry. I see these EVERYWHERE among wreck divers. They are cheap, small, razor sharp, and just work... Under five dollars...

http://newenglandmarine.com/products-page/browse-by/dexter-net-knife/


One of the reasons we like the above so well is that it fits this sheath, which has a belt loop but also grommets to allow sewing or riveting onto your gear:

http://newenglandmarine.com/products-page/browse-by/dexter-plastic-sheath/



There's another competing brand that has a name that escapes me at present, with a blue sheath, that we also use with perfect satisfaction. They are also Swedish. If I remember who makes them I'll post their name also.



Willie

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[Willie Sutton]

^^

Noting further that I don't see too many Emersons offshore ... ;-)


Willie

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[Shanghai McCoy]

Long, long ago I was a Navy Diver. No, not a SEAL, salvage...
All we usually carried on our belt was an issue Kabar with lots of grease on the blade. This was while diving with scuba or with the old Jack Brown rig and I seem to recall that we'd strap one on the hard hat rig too since all the "Official Navy deep sea diver knives", like that nice Desco one Willie linked to, got "lost" on the bottom .

After I got out I carried a Solingen stainless dive knife while taking out tourists in Hawaii. Lots more useful tools available these days that is for sure.

Hey Willie, know any retro divers that are in the market for a Conshelf 12 regulator..?

 

[Willie Sutton]

^^

Absolutely, on both the old school use of a Kabar with grease and guys wanting Conshelf's. Guys still like them. Bet you don't know that the guts are the same as the Voit MR-12, and still are available.

I've got a Jack Brown mask sitting right next to my Mark-V in my den... along with an Emerson 02 Rig and a set of the EOD aluminum 1958-vintage doubles with the black non-mag Royal Aqua Master reg sitting next to those..

And it *is* amazing that those DESCO screw in knives were regularly lost.. sheath and all...

Willie

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[Shanghai McCoy]

Hey there Willie.
Thanks for the info I had no idea that the old stuff was still useful ? Might have to do down to the basement and dig out the old dive bag.
I still have my kabar but the leather washer handle gave up the ghost a long time ago. I need to get some of those replacement kits and re-build it.

Oh man, aluminum doubles... no wonder my back and shoulders are screwed up these days. Your den must look like a museum, spent a lot of time with the Jack Brown rig while stationed on a sub tender and the MK 5 on a sub rescue ship.

And yes, the ocean bottom MUST be littered with lost Desco knives still in their grease packed brass sheaths. But probably with broken straps .

 

[Nom de Forum]

I got my NAUI certification in 1973. Back then most of us thought we needed a 6” to 7” knife with a yellow handle (so we could see it when we dropped it) all because we had seen too many episodes of Sea Hunt and because that was what U.S. Divers was hawking. Nothing Willie has posted about what really works for diving today can be reasonably disputed. Times changed long ago from the days of most divers thinking they need a knife that resembled something a commando might use to something that is practical.

 

[Icky The Great]

When I received my Cert my mother bought me the skeleton knife...
http://www.spearfishingworld.com/stainless-steel-skeleton-knife.html
I had already picked up a Kershaw Amphibian with dive sheath for $30 bucks and found 2 more at a flea market with boot knife sheathes and picked them up for $10 each.
http://www.midwayusa.com/product/58...s-steel-blade-and-handle?cm_vc=ProductFinding
They used to make the Amphibian with a chisel tip and I regret not getting on when I saw it. However if I begin loosing knives I may just stick to the skeleton for price and simplicity. My good friend recommends Omer Ministil. He does a lot of spearfishing so it gets a work out. He has only lost one in many years when the lanyard broke.

 

[hso]

Directed at no one in particular - Regurgitating marketing spew from the internet is pointless. IF anything from the net is worth regurgitating it would be from SCUBA diving forums and online SCUBA retailers customer reviews, and would cite those technical and customer reviews. THAT might be useful since those reviews would be worth repeating as opposed to marketing pap. Without direct experience the best authoritative sources are from people who have been there and do that and they're luckily clustered on the dive forums and the dive equipment sellers.


I'm NAUI, my wife is PADI, my daughter just got SSI certified on New Years in the Caymans. I got my card about 26 years ago.

 

[Shanghai McCoy]

Dug around and found that old DACOR dive knife. It must have been a good knife since I was obviously hard on it based on the condition it was in when I put it away. No rust on the blade though.
Amazing what applying bit of grease before long term storage will do for a tool...

 

[Willie Sutton]

Ahh.... Dacor.

Sam Davison was one of the real pioneers of diving, and DACOR was DAvisson CORp. Based out of Illinois, and made great stuff. Sadly... too good and too costly to compete with cheaper stuff. I used their knives as well in the dark ages.



"Without direct experience the best authoritative sources are from people who have been there and do that ."


Yup.

The first attached pic is me dressed into a Cis Lunar Mk-5p rebreather preparing for a dive on the USS Monitor off of North Carolina for a research survey done under a permit issued by NOAA. I blacked out my face, as the pic is not about me: Circled in red is one of the cheap blue-handle Mora knives, the best tool for the job. The rebreather I am wearing sold for about $25K. The knife cost $8.00: The Practice of using a cheap knife is done because it's the best tool for the job, not because we are price sensitive in our gear selections.


The second pic is me sitting ready to jump on the wall down in Grand Cayman, in my sport diving gear. Notice the circled in red "cheap knife" which is one of the ones I linked to in my post above.


Third image is prepping to jump on the wreck of the Carl D Bradley, in Lake Michigan, with an ISC Megaladon rebreather, which is the same as the USN Mark-28 rebreather. At 380 feet of ice water, the Bradley is the second largest wreck in the Great Lakes. Notice the small knife circled in red on the waist strap. Notice also the dry gloves and drysuit. We use blunt tip knives here so we don't puncture our suits or gloves. A tear in a glove before needing to do a 3 hour deco hang in ice water might be lethal...electric heat in the suit notwithstanding.


What works, works. This is the big leagues.


Willie

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[Field Tester]

How well would something like a Razzle work as a Dive Knife?

 

[Willie Sutton]

Knew I had a shot of this... here's how to rig a Mora knife with retention while keeping it easy to get free quickly. Photo take of me at Watch Hill RI getting ready to do some freediving spearfishing. This is the bungee method that I described above. In this case the sheath is simply taped to the harness with electrical tape.



Willie

 

[hso]

What you carry depends upon what you want to do with it, and what you don't.

Sometimes the "don't" part is more important. You don't wan't to poke a hole in something you don't want a hole in, like you or your gear, so you find many dive "knives" have blunt tips. For every blunt tip out there you'll find more with a point, but you're probably never going to use it while under water (regardless of how many times you've watched Bond movies or Jaws).

You do want to be able to cut line and net so you find many of them have serrated blades these days and they used to have line cutters.

You don't want to have them rust so the steel is higher chromium content and since you're not using them to cut all the time no one cares terribly about edge retention particularly. They just need to cut that one time you need it.

You may want to pry so you'll find pry tips and stronger blade bodies for those applications.

You don't need a big long blade so most are around 3-4 inches these days and 20 years ago they were starting to get shorter than 5 and 4 inches (although some old timers carried bigger because that's what they started with).

Your hands can be cold and not grip terribly well at times and you want a handle that will be grippy even when you aren't so you find a lot of hand filling grips with rubbery inserts or coatings. Not as big a deal in the Caribbean, but the Pacific can be cold even in the summer and diving in the winter can get awfully chilly.

You don't want them to come loose from the sheath while you're fumbling around trying to waddle to the "giant stride" or trying to climb onto a dive platform in 8 foot seas (or in your dive bag with your BC) so you find a lot of attention to sheath retention, BUT because in an emergency where you need it to help you get untangled from a line or net and your hands are cold and stiff the retention needs to be something you can operate easily so they tend to be very obvious.

You don't see folders much because folders are something to have to manipulate so you see sheath knives most of the time.

Most "dive knives" never get used for anything so they're designed to "catch" divers, but some do get used and sometimes they save lives.

I've watched the evolution of dive knives over 20+ years and saw EMT shears come into use and thought "DUH, of course". There are even dive focused versions.

All of that speaks to recreational and scientific diving instead of commercial.

If the Mora SamC showed had a better retention system it would fit the bill for a lot of what is needed.

 

[hso]

Willie,

Did you use bungee or surgical tubing? I've seen a lot of tubing get used, but not a lot of the real bungee cord (although my wife just sewed up new jet ski covers and bought marine bungee to run through the skirts).

 

[rcmodel]

What about the new modern Braided fishing Line like 'Spectra'.

From what I understand, They take carbide edge cutting pliers to cut them.

http://www.torotamer.com/toro_tamer_accessory_products.htm

rc

 

[ugaarguy]

What about the new modern Braided fishing Line like 'Spectra'.

From what I understand, They take carbide edge cutting pliers to cut them.

Spectra is one of several High Modulus Polyethylene (HMPE) fibers that compete with Aramid fibers like Kevlar. Carbide edge pliers, or (ideally) ceramic blade shears are needed for repetitive cutting of both of these types of fibers. However, they can be cut with conventionally blade steels in an emergency. So, a replaceable blade line cutter like a trilobite or a well maintained conventional dive would still work. I know that from experience on dry land cutting through Aramid and HPPE protective jackets that surrounded the fiber optic data cables I had to repair.

 

[rcmodel]

O.K. Thanks!

I just didn't have much experience with it before I stopped fishing.

It was some pretty tough stuff I sure wouldn't want to get wrapped up in though!

rc

 

[Willie Sutton]

HSO asks:

Did you use bungee or surgical tubing? I've seen a lot of tubing get used, but not a lot of the real bungee cord


It's funny: The retention for the Mora is about the only place I find that cloth based rubber cord bungee works well in diving. If you look at the photo of my spearfishing rig, you'll see that the loop is not tight at all, in fact when the knife is in it's sheath the loop is actually hanging free, not tensioned. It's "just enough" to keep the knife from being lost.

Go click on the photo of me in my freediving gear and open and then click to magnify the knife. You'll see the green cloth bungee and see how it's set up.


For everything else I use latex rubber surgical tubing bought by the 25 foot length from McMaster-Carr. I use 3/16 diameter with a thin wall. Within the scope of this thread, it's use is to make two small wrist-loops for my dive computers to replace their original straps, as with a 1000% + stretch they can be pulled over anything from a bare arm to the wrist ring of a drusuit fitted for dry gloves without adjustment. Before I knot the loops I slip each of the tubes thru the attachment loop on the sheath of a Trilobite cutter, and now I've got a cutter laying right under my computer as I look at my wrists. I wear an identical computer (Shearwater) on each wrist and I consider these two cutters to be my primary knives. Nothing is as close at hand and visible as the opposite side wrist.


Willie

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[hso]

Yeah, the handle loop should only need to be tight enough when pulled down over the sheath that it would keep the knife from coming up out of the sheath an inch or so before it started to pull the knife back down. "Ideally" it would be just long enough so you could pull the cord down and release over the sheath when you had time while still being able to grab the knife and pull it clear with force and then let it down to clear the loop from behind the sheath if you were in a hurry (although we never want to get in a hurry when diving). That looks like the length you set for the mora. Is that about right?

Why do you think the bungee is better than surgical tubing in this application?

 

[Lone Star]

I do think weapon potential should be there. Besides sharks, there are many other marine and fresh water denizens that might require a knife to deal with.

Microfilament and other line is an additional hazard, and I gather that kelp can be.

I once wrote an article for a knife magazine for which I researched incidents in which a knife or spear had saved divers' lives. I went through a variety of books on sharks and found a number of such cases. All seemed well documented and often included the diver's name. One good one that mentions knives is the late Thomas Helm's, "Shark", long out of print. Helm had a handmade knife that sounds like a Randall, although he didn't mention the brand. He noted that the blade normally held an edge very well, but that if used to skin sharks the dermal denticles in the hide dulled the knife pretty fast. Worth noting, although it applies to skinning sharks; not to stabbing them.

Knives that I'd look at include Fallkniven's A-1 and S-1 and SOG's original SEAL 2000 and the old Puma dive knife, although the latter is becoming quite collectible. It's the one used by Lloyd Bridges on, Sea Hunt, with a D-guard.

If one takes care of his knife, a costly one isn't a disaster and is more pleasing to own. My son is PADI certified as a master diver and did quite a lot of diving off of Guam. Much involved spearfishing. He mentioned the need to SCRUB the blade after salt water exposure, not to just rinse it. You need a sponge or toothbrush to scrub the blade under running fresh water. Then dry the knife and oil it.

His knife never rusted, so treated. His friends were more lazy and all had rust.
He says that few divers are really "into" knives and most buy cheap ones that don't take or hold a good edge.

I had a Randall Model 16 and liked it, but had to have the edge bevels reground to a keener edge. Gary Randall told me that he delivers the edges relatively thick because so many divers dig with their knives and otherwise abuse them. I don't think that's a good idea. A pry bar is wise if you'll pry or dig. If you need a knife, you need a sharp one.

One factor to consider is which knives are legal where you dive. That never seems to be on the agenda when dive knives are discussed. Maybe that's because most think of them being employed in the open ocean.

I think dive knives need a lot more thought than most divers give them.

 

[hso]

Lond Star,

Did you find that the incidents of "defensive" use were a very low percentage of the hours spent by divers and that the percentage of incidents were so low that those anecdotes were exceptionally rare and exciting?

 

[Lone Star]

The references didn't say (who has really ever tallied that, and how could they, given the lack of reporting to any central source over hundreds of years) , but it takes just one such incident to cost a life or a limb if the right knife isn't there, and well used.

Nowhere did I say or infer that divers constantly have to fight off sharks, etc. on every dive. But when it happens, you'd better be able. In addition to attacks on oneself, a companion may need help.

One such incident was tragic. A teen tried to come to the assistance of another person being attacked by a shark off of California. The lad had a war surplus M-3 trench knife that wasn't very sharp and he wasn't able to stab effectively. The result was that the boy under attack was killed.

In another case, a South African angler came to the assistance of a friend being attacked by a Nile crocodile. He wasn't able to stab through the armored hide, but pierced an eye, at which point the croc promptly retreated in evident distress. If memory serves, the rescuer received a lifesaving award for his gallantry. I think he deserved it. BTW, these were not poor Africans; they were of European ancestry and I have no idea why they didn't have firearms. The article didn't address that issue.

Ridiculing the idea that a knife may be needed doesn't mean that it sometimes isn't. How often do most pilots really use a parachute?

 

[hso]

Lone Star,

There was no intent to ridicule, just interested in what you thought the percentages were since you'd done the research.