Dive knives when out with a DM

[Here There be Lobsters]

I strap a big knife to my thigh and end up using it 40%-50% of the dives I am on. Typically it is handy to free myself or wildlife from fishing line, collecting old fishing lures, and cutting or releasing zip ties. When lake diving, I use it to kill invasive clams.

 

[Gone for diving]

Love knives, have carried one ever since my parents let me,
Given my occupation I always carry my leatherman and a flashlight...
People laugh, but always seem to ask me for a knife or a flashlight...
I use the pliers more than the knife...

I would wear a BFK (which I have lots of) diving...
But it's just an other thing to strap on,

I am about donning the least amount of stuff,
So I try to consolidate everything...

I carry one knife on my dive computer and set of ss pruning shears on my crotch strap.
They definitely have served me well over the years..

 

[nippurmagnum]

All right — this happened to me on a night dive in Roatan. There were about eight divers jumping into the water, and several of us had knives. We jump in, start our dive, and after just a couple of minutes I see a diver in our group holding his knife in his hand, like he’s Rambo and looking to stab someone. WHAT A JERK, I think, and try to put as much distance from him as possible. FIFTEEN MINUTES LATER, I SEE HIM AGAIN, AND HE STILL IS HOLDING HIS KNIFE LIKE HE’S RAMBO. Again, I put as much distance from him as possible. This happens several more times, and by the end of the dive, I see that he is still holding his damned knife, so I decide to get back on the boat last, and avoid him to the very end. When I finally climb onto the deck, the smiling Rambo guy walks over to me with a smile, holds out a knife, and says, “this may be yours, I saw the knife under our boat when we jumped in.” I look at my empty calf knife sheath, and say, “oh, thanks.”

 

[boulderjohn]

These early cave divers did come up with a lot of good ideas and methodologies and the concepts (not necessarily the exact equipment) are as applicable to open water as they are to penetration diving.

My take on this sort of thing is that if you go back a half century ago, divers were trying to figure out the best way to do things, and kicking techniques and equipment evolved slowly over the next few decades. This evolution, though, was not universal. The people doing caves evolved different techniques and equipment from the people diving in open water because they had to. For example, both developed the idea of an alternate air source, but since the cave people knew that they would have to make the exchange under tight circumstances and exit single file, they developed a different system. The same is true for all those differences. When they started, all divers were using the same equipment, but the changes that came along later were in response to different dive environments.

 

[Nemrod]

My take on this sort of thing is that if you go back a half century ago, divers were trying to figure out the best way to do things, and kicking techniques and equipment evolved slowly over the next few decades. This evolution, though, was not universal. The people doing caves evolved different techniques and equipment from the people diving in open water because they had to. For example, both developed the idea of an alternate air source, but since the cave people knew that they would have to make the exchange under tight circumstances and exit single file, they developed a different system. The same is true for all those differences. When they started, all divers were using the same equipment, but the changes that came along later were in response to different dive environments.

I follow and agree. But credit where credit is due, these cave folks were at least partially responsible for:

Modern wing and backplate BC
Single piece harness
Long hose primary (40 or 60 inches for open water)
So called streamlined rigs (no consoles, dragging octos, BFKs on the leg) with everything in it's place
B&G spgs
Team diving
Deco acceptance
Can lights
Slinging cylinders
Side mount (dangle mount, lol )
Isolation manifolds
And then I suppose GUE, DIR and all of that.

And I think these early guys also helped push the envelope that eventually led to wide mainstream use of trimix/nitrox and CCRs and "Technical" recreational diving.

This trip to Florida, which is not really over yet , I saw and have seen more BFKs strapped to legs since the 70s. I guess I should pull out my Sea Hawk for my next dive, just in case a Great White needs to be attitude adjusted or a manatee needs harassment.

James

 

[iofnewt]

A dive knife is versatile, it cuts lines and net easily and can be use for signaling when prearranged by hitting the tank. It can emit and audible sound for some distance. Also can be used for eco location if separated from buddy or group and they respond to your "clank" signal. This served me well on one occasion of low visibility. It can also be used on a boat as a....knife. I have a TUSA I bought in 1992. I do not take it on every dive, but I certainly want to have it outside the reef. I doubt that I would ever need it for defense. It is a tool. Sometimes you just need something to help in maintaining gear or slicing mangos.

 

[John C. Ratliff]

I have been using a BFK all my diving life (1959 to now). Here’s an example where I really needed one while in the USAF as a Pararescueman:

"March 17, 1969

"Dear Mom, Dad, Skip, Bill & Ken:

"In my last letter, I told of our water training that we conducted a week ago last Thursday. Thursday last, on a mission we would rather wouldn't happen, we tested our procedures and found them very effective. It was stormy on the 13th of March when we received the scramble call. A T-33 jet flying from Kwanju had called into Kwanju with engine troubles. We scrambled with the fire suppression kit and orbited near the runway. A storm just off the end of the runway put visibility down to zero, with some icing. The ROKAF T-33 never landed, and Kunsan AB was unable to establish radar or radio contact. We landed, I got my skin diving gear, then went out for a search. After 15 minutes we found the victim’s life raft and helmets. No sign of life was observed. We landed in a mud flat, where the pilots and flight engineer (FE) put on exposure suits and I put on diving equipment. Then we went out for the recovery. The rest is in the rough draft statement I wrote for the ROKAF Accident Investigation Board.

___________________

"1625/JCR, Mission # Det 3, 41st ARRWg 007, March 13, 1969

"I had very little visual contact with the victims or their equipment before my deployment into the water because I was busy putting on my diving equipment. I was in the door about 10 seconds before TSgt Maxwell tapped me out of the helicopter. The helicopter was in about a 15 foot hoover when I jumped. After entering the water, I swam to the victim and tried to lift him to the water's surface. He was too heavy. Underwater visibility was about six (6) inches. It was hard to determine which part of the victim (arm or leg) I was holding. It was his arm. I found one of his Capewell quick releases for his parachute, which was deployed in the water, and released it. Then I turned him over to get to the other release, and released it also. I tried to blow up his LPU,[1] but couldn't find them. The victim's face was bloody and he didn't have a helmet on. After releasing the parachute, I swam him away from his life raft and parachute. I had to cut parachute suspension lines which were tangled around his feet and my swim fins and the tether to his life raft. I signaled for a helicopter pickup of the first victim. The HH-43 helicopter lowered a rescue seat to me, which I disconnected, and hooked the hoist's hook to the victim's parachute harness.

"After the first victim was aboard the helicopter, I looked around for the other victim. I saw a helmet, swam to it towing the rescue seat, but the victim wasn't there. I strapped the helmet to the seat. The second helicopter guided me to the second victim.

"I swam to the second victim, swimming around his parachute to keep from getting tangled in the lines. I found some suspension lines beside the victim and cut them. I then cut the risers (on the victim's right side, I believe), disconnected the Capewell quick release from the parachute risers on the other side, and checked to see if the victim was tangled in lines. He was not tangled. I also tried to locate his LPU to blow them up, but again couldn't find them. Then I signaled for a second hoist pickup, which was accomplished the same manner as the first.

"When the second victim was aboard, I swam to the rescue seat, strapped myself into it, and I was picked up.

"Headquarters
Republic of Korea Air Force
Seoul, Korea

"[1] LPU--Life Preserver, Underarm"
I will attach a photo of the Sportsways knife I used (which I kept razor sharp) and my current knife. But I won’t dive without a BFK, as this tool has helped my stay free of entanglements numerous times.

 

[boriss]

I find it interesting that some people have only had to use their knives/cutting devices once in thousands of dives. I'm new to diving and I've already had to use my Trilobite twice when tangled in fishing line on a wreck. Once while going through a tight restriction inside a wreck. That honestly scared the crap out of me. The line caught me and wouldn't let me continue forward. Was easy to cut it, but the timing sucked... scared me a bit.

I've used a BFK during rescue class to hold against current, but more importantly, to mark location when doing our search pattern.

Lastly, I've seen people get tangled in their own line, that had to be cut apart. Many people have died from entanglement in cave line, fishing line, rope, etc. IMO cutting devices are pretty important and I never judge people for what they bring with them. What's that saying? It's better to have it and not needed, rather than need it and not have it?

 

[Wibble]

Love knives, have carried one ever since my parents let me,
Given my occupation I always carry my leatherman and a flashlight...
People laugh, but always seem to ask me for a knife or a flashlight...
I use the pliers more than the knife...
View attachment 734682

I would wear a BFK (which I have lots of) diving...
But it's just an other thing to strap on,

I am about donning the least amount of stuff,
So I try to consolidate everything...

I carry one knife on my dive computer and set of ss pruning shears on my crotch strap.
They definitely have served me well over the years..

Leatherman question: how well do they work around seawater? Do they rot over time or is the stainless steel good quality -- including the rivets?

I ask as they're undoubtedly great tools, but if you can't abuse them in the sea and not constantly rinsing them then other tools would be better.

(Have never owned one so genuinely interested)

 

[Nemrod]

Many people have died from entanglement in cave line, fishing line, rope, etc.

I am not sure about that.

But you do make me recall one incident. I was 18 years old or so and I was helping to set up a water ski slalom course for an upcoming event. It was near Valdosta, Ga., it may have been at Twin Lakes, not sure. The water was about 6 feet visibility and the lake itself was 15 to 30 feet deep or so. I was breath hold diving, not SCUBA. I had swam down to set an anchor point line and as I finished I began upwards and came to a jerking stop. I looked down and could see that somehow I had tied the anchor line, heavy polypropylene line, around my ankle. But this was in the era of BFKs and I had (and still do) my USD Sea Hawk BFK. The serrated edge made quick work of the line. Would I have drowned were it not for my BFK, probably not but the rope had some sort of complicated knot in it that included my ankle so best I did not find out if I could untie it. I had forgotten all about that completely.

"Many" people, hmmm, not sure about that. I think it pretty rare.

Not that day or course or event, but me on a slalom competition:



James