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Safety - knife

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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Aquatic shopper...
Jul 3, 2003
I have been in the sea quite alot in my life but went out with my cousin the other day.

She is more into scuba but comes with me snorkelling/freediving sometimes.

Anyway, she had a knife and told me why : got caught in some line underwater (scuba) so was able to cut herself free.

What I would like to know is this : is a knife a knife or are there better ones to get ?

I would be mostly using it for safety but perhaps the occasional spearo session too. I have been looking at the Diablo Razor - any one any thoughts on this or other knives ?

Cheers for any help - think I should really buy one in case of coming across monofillament at depth (well shallow depth at any rate :) )
I used to get caught in my safetyline all the time :eek:

Well I don't use that anymore of the same reason, the thing that is supposed to keep you safe is trying to kill you! No thanks.

As for knife. Get a small one, I know there is no Rambo effect but you won't mind having it on, and therefore you will more likely use it. I wouldn't pay to much for it, there is allways a risk of loosing it.

But after beeing suprised by fishing nets a few times I will never dive without a knife.
Check out the spearfishing section of the forums. There are some pretty in-depth discussions about knife types, steels and placement of knives.

Good Luck

Get a light knife, with a flat point. That way when you do go
slashing wildly you might not stab yourself. 90% of the time if
you are tangled it is faster to calmly untangle yourself.
I've found that when I do have to cut myself free it was because
I struggled or the line was tightly wound around my legs...by mermaids I guess.
One more thing, If you ever lose the knife be sure to observe
the rule and throw the sheath in where you lost the knife.
I have three knives without sheaths:)
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Cheers for the info

In the end I went for a Technisub Diablo Razor - not too expensive and good for the occasional spearo session as well as slashing wildly at underwater obstacles.
Got stuck in some fishing line last night - just about to go home and found I was a bit caught up in old fishing line. It was around 9:30pm and getting a bit dark. Glad I had a knife. Buy one if you fool around in the kelp !
A knife for spearing and a knife for safety are seperate, IMO. For a safety knife I would want something with a serrated edge and a sheepsfoot or similar point to prevent poking. Look at the knives whitewater kayakers use for some decent examples. Something like this or this.

A knife for spearing and killing fish needs to be pointy to penetrate a fish skull quickly and efficiently. Some people forget the edge, and just use an ice-pick.

Dive knives have notoriously thick edges and are often hard to put and edg on, and keep. If you are looking for a safety knife, I would like to see you get something built with that intent, rather than something that tries to do everything.
Couple of things here. First I don't think someone should be slashing wildly whether it be on SCUBA and especially freediving. If you are freediving then you will effectively burn up your oxygen "slashing wildly". Kinda similar to flailing wildly while swimming. Second you difinitely needed a pointed knife with an edge for the spearo session. True that you can ice pick a fish's brain but what if you get caught in line, kelp, or whatever? That ice pick would be useless then. Third a dive knife isn't that hard to sharpen. And lastly, I checked out the diablo razor and I think its a pretty good all around knife and a good choice.

I was kidding about the slashing wildly,
I've just seen it happen when divers get caught in kelp and lines.
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I have snagged a buckle a couple times when I used to wear open heel fins. I also got caught up on some mono that hooked over a lead bullet on my back. it is also not inconceivable to get tangled wile sourounded by aquatic plant-life or in a spot of restricted motion or visibility. In a situation like that one may be forced to cut themselves free by feel, without the ability to see clearly what you are caught on or up in. It is also conceivable that you will have to cut close to your body, even sliding the blade along your body to get under the impediment. Considering this, I want a knife that will cut efficiently and some sort of safer tip. If something else works for you, fair enough.

Not all dive knives have poor edge geometry, or steel, but your average 416 or 420 stainless hardened to the 40's is far behind some other solutions for edge-holding, and sharpening. That doesn't mean that 416 or 420 is incapable of getting job done, rather that more effort may be required in putting a propper edge on it and keeping your blade that way.

Personally, when I look at what sort of things I am likely to get caught up in, I want the sort of knife that could slice a tomato, rather than pry off a car door. What you need may well be different.
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Brad / w3ac - the slashing wildly has been taken a bit too litereally ! Just a flippant remark - however, there would come a point when you might slash wildly - say after a couple of minutes, reason would go.

Hephaestus - the Diablo Razor that I bought has a good edge, it can slice tomatoes (and radish for that matter, in fact it is a pretty good all round salad implement). However it also has a line cutter (a sort of u shaped cutter) and a serrated part for presumably sawing body parts off if you get really stuck.

I looked at other knives and short of carrying an arsenal of blades and a caddy of guns I thought I'd get something that could work for alot of situations.

The handle is nice and comfortable and the straps are good and it snaps into place in the holder well. Doesn't rust, holds it's edge and slips under the pillow without snagging. What more do you need ?!

Some of the safety knives have very thin handles or handles that continue from the blade, I think these would be slippery in an emergency but have not tried them. (I oftern wear gloves)

The point is not too much of an issue - and I need one more than not having a point. It is better to have a point than to have no point at all. In my opinion. (Some of the grey mullet in these parts grow large and can be agressive, I would prefer to have a knife with a point for defensive purposes too).

The Diablo Razor that I bought is not too expensive, it is reasonably fluid-dynamic and I can grab it really easily.

Anyway - I guess the alternative is to buy a safety knife and carry a fish loop with a sharp spike. Depending on the fish size this would work.

At any rate - any cutting blade is better than none.

It sounds like you have found your solution. Now that you have a good knife I hope you never have to use it!

Take care
Originally posted by portinfer

the Diablo Razor that I bought has a good edge, it can slice tomatoes (and radish for that matter, in fact it is a pretty good all round salad implement

portinfer, you really have missed the point havent you! You have the BBQ when you leave the water :duh

Sorry :D
Alison - true enough - I think the Diablo might work for flipping burgers too ...
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