What is the purpose of a diving knife?

[impulse]

Hello,

I got a padi rescue certificate and i try to dive as often as I can.

Through all the training I had about scuba diving, my instructer pointed out the importance of carrying a knife.

I really do not like that kind of equipment and wonder if it's really an important thing to carry a knife while scuba diving. What would be the situations that could be encountered that needs a knife to escape and stay alive? What is the real purpose of a diving knife? Should I really carry one while scuba diving? Thanks in advance for your oppinions.

 

[diver 85]

think :jaws------nah---- for cutting, prying, & general sorts(shears can/will do the same)..........why do you "not like that kind of equipment " if I may ask?....

 

[impulse]

I do not like because when I carry a knife around it looks savage. Especially the bigger ones. I once had a mares tris which I lost during a dive. That was like a big weapon and I was ashamed carrying it so I mostly kept it in my diving bag. Maybe I need a smaller one?

 

[diver 85]

I do not like because when I carry a knife around it looks savage. Especially the bigger ones. I once had a mares tris which I lost during a dive. That was like a big weapon and I was ashamed carrying it so I mostly kept it in my diving bag. Maybe I need a smaller one?

Yep---years ago had several of the 'big, leg strapped ones' & now simply carry a 4" small one in my BC pocket along with some shears clipped on a D ring....no big deal.....99.99% chance you'll never injure anyone, including yourself.....

 

[FireInMyBones]

As for looking savage, I carry at least one cutting tool, most times 2 at all times, even when not diving. Most people would not know where to look other than my wife or dive buddies.

Seriously, a z-knife or shears will work in most cases, they have gotten me out of two entanglements before. I have only used my knife as a tool to pry lodged teeth out of the settlement and in an underwater pumpkin carving contest (took second place). I keep it in its sheath not to be disturbed unless needed. I use a cheap paring knife from walmart with the end sanded off and in a homemade sheath. If I loose my knife, I do not chase it, I replace it for $1.50.

I hope that helps. To clarify: my main cutting tool...shears.

 

[dkktsunami]

I carry one small knife (blade 1 1/2 in.) and one very small emt shears carried in a manner that both are reachable with either hand. These are not weapons but tools and are used to free myself from possible entanglement (fishing line, dive reel, etc.). I frequently dive solo but, other than that, not too much of a savage.

 

[miketsp]

In a few hundred dives I've only needed a knife a couple of times and each time I wished I had something bigger, like a hacksaw!

The worst time was I'd just giant-strided into the water from a live-aboard and they suddenly realized the fore anchor had pulled loose and they were drifting towards the rocks we were about to dive. They tried to maneuver and in their rush forgot they'd launched the dinghy with a stout 1/2" cable at the stern. After winding on about 30 turns round the prop shaft this locked up.
As the only diver in the water and with the boat about to go aground they asked me to clear the prop ASAP.
Even with a long blade and alternating between the cutting edge and the serrated back it was hard work and touch and go. The cable was stretched taught. I just managed to clear it in time.

If I'd had only a pair of snips or a z-knife or a dinky little BC mounted blade we'd have been looking at a new wreck dive.

 

[SurDo2]

I do not like because when I carry a knife around it looks savage. Especially the bigger ones. That was like a big weapon and I was ashamed carrying it so I mostly kept it in my diving bag.

Who cares what you look like. It's there to save your life if need be. I don't understand how an inanimate object that is a usefull and necessary tool can make one feel ashamed. Please advise.

Cheers.

 

[Walter]

It's a cutting tool. What might you cut on a dive? Fishing line? Use tin snips. Rope? Use a knife with a serrated blade. Fish throat? Use a pointed knife with a sharp point.

 

[impulse]

I cannot advise you about that. It's just a feeling. Becasue I am new to scuba diving and I am not sure if it's the right thing to carry a big knife on my lower leg. I am not really familiar with it. Ok that's the question. In what cases a diving knife would really save my life? For instance during a moray eel attack?

My problem is I cannot imagine the possible bad situations. I cannot understand how one can entangle into for example a fishing net during a proper scuba diving. You see it right there but still entangle? I think this is a stupid question but that's what I want to ask, just to get informed about the subject.

What is the ideal size of a diving knife? Maybe I must buy a cressi-sub orca? Is this one too huge to carry out?