First Dive Knife

[bomberkenny]

I have a trilobite on my computer strap too

 

[FF / EMT]

Ask yourself a few questions:

• What hazards will you encounter?
• What gloves will you wear?
• Where will you be able to reach a knife most easily?
• Will you spearfish, or will you look at fish?
• Do you enjoy gear maintenance?
• Would you endanger yourself to save your knife?

Hazards: I see you're from Idaho; will you be diving locally in lakes/reservoirs? If so, your main cutting need will probably (not exclusively, but probably) be dealing with monofilament fishing line. A line cutter (e.g., Trilobite) will do nicely for that. If you're going somewhere that might require you to cut something more sturdy, or to use a knife as a prybar, then get a fixed blade.

Gloves: You wrote that you're currently wearing 5mm gloves. Those are inherently clumsy, so manipulating a folding knife can be challenging. If you're going to continue diving cold waters, I'd go with a fixed-blade knife, preferably one that locks/straps into its sheath and that's deployable with one hand. If you're going to travel to warm waters, though, you'll probably go bare-handed or just wear thin gloves, so a folding knife would be easy to deploy.

Reach: Whatever cutter you get, put it somewhere that it's comfortable and convenient for you. A BFK will fit nicely on the inside of your calf, preferably on the same side as your dominant hand. It's less likely to catch on entangling hazards there, and you just have to draw your leg up/reach your arm down to find it. A small knife should attach anywhere that requires a short, non-contorted reach; a BCD's corrugated hose is one popular location. If you have a wrist-mounted computer, get a line cutter and put it on the computer's wristband.

Spearfishing: If you're going to poke fish with pointy sticks, you want a straight-up dagger to finish them off. Otherwise, go for a blunt-tip knife. You're less likely to stab yourself (or your BCD, or your drysuit) while putting it away.

Maintenance: If you're the sort who loves to love his gear, get a stainless blade. If you want to rinse-and-forget, get titanium, or just get an inexpensive stainless knife and rinse-and-forget until it gets rusty.

Endangering yourself: Remember that a knife is disposable equipment. You want one that you won't cry over losing, or that you'll do something risky to retrieve once (not if) you drop it. Save your money for something really important and that won't tempt you to endanger yourself.

I carry a dog cutter recon and a pair of trauma shears, if I have to use the knife for anything, I’m dropping it to
My side, not going to mess with it and puncture my suit.

 

[S3dition]

I'm not an expert, but in selecting my first knife, I considered laws for where I'll be diving.

Japan has strict laws around knives and tourists have been jailed for breaking them. In addition, many places won't allow you to dive with a knife or gloves so you won't touch the wildlife.

With this in mind, I purchased a 3" blunt knife that I can stow in bcv or strap to my leg. It is a $30 titanium coated blade l

My second knife will be a ~6" titanium that I can leave home when necessary. I know I won't be damaging the ocean but I don't know if I'll get Tangled in fishing line.

 

[seashepherd]

I’m a newbie, and just went through the selection of a knife. It was fun looking at the options. In the end, I picked a simple 3” blunt end SS knife that wasn’t too expensive in case I lose it. I bought a simple leg sheath made of neoprene that was inexpensive as well, to fasten it to my leg. I think of it as a safety tool, but I have visions of Sea Hunt when I strap it on. It’s very inconspicuous, and it’s there if I ever need it.

 

[Scubagolf]

Trauma shears in the pocket of my BC attached to inside of the pocket.

 

[Silvertip57]

Gave up on dive knives after about 20 dives. Just one more thing to attach to body or BC. I carry a pair of blunt nose SS scissors in my BC pocket for mono or net cutting. Just my 2 cents.

 

[TMHeimer]

I have always used the basic small knife. Not sure what material. Strapped to inside of leg above right knee. I also tie it there with a rope. Also attach fishing line from the knife to the holster as I lost my first knife on a dive as if came out of the holster. The line is long enough so the knife comes out easily but no extra length floating around. If I need the knife I can just break the fishing line. in 784 dives I have never used the knife (almost did once in Texas due to fishing line, but didn't need it to get free, and there is no fishing line at the sites here). Thus, I don't give the knife much thought. Guess I've rinsed the thing 300+ times now without ever needing it. I do kinda think some sort of siscors/cutting tool like that seems like a good idea.

 

[Subcooled]

What is a good dive knife to get?

Where are you diving? In what kind of stuff can you get entangled in?

The sea: fishing nets - get scissors
The sea: filament - get scissors or a rescue cutter
The pond: It's probably a dump with barbed wire so get wire cutters
The flooded pit or former quarry: OK, there will be trees down there... How about a saw?
The yacht port: It's probably dyneema so forget about cutting. You need to rip it apart thread by thread with pincers (I did just that)(wasn't recreational diving though) But how can you get entangled in that??? Its an inch thick...

A sawtooth blade (some cheap kitchen knife) would be lovely in many cases where a sharp straight blade just slips. A blunt tip is good as one does not need/want to puncture things (like a suit) but to cut things.

Titanium does not rust but it is expensive. Stainless steels comes in dozens of varieties. I have heard 316L is good.

A short answer: a cheap rescue cutter is always a good investment. I have one. I love it. If you prefer knives, get a cheap beef knife with a sharp sawtooth blade and cut it short. A plastic tube acts as a sheath.

Getting entangled in something is quite rare, especially in open water recreational diving, but if it happens one would love even nail clippers... I have dived hundreds of times and sometimes in quite nasty places and only once have I needed a cutting device (to recue a buddy). ANY sharp blade would have been enough.

 

[Storker]

Titanium does not rust but it is expensive.

..and it's pretty bad at holding an edge. Worse than even decently corrosion-proof steel. If you're able to get a half-decent edge in the first place.

Stainless steel: always a compromise between edge-holding properties and rust resistance.
Titanium: corrosion-proof, but sucks at getting and holding an edge.
Ceramic: corrosion-proof, wonderfully sharp, but chips for a bad word.

Pick your poison. TANSTAAFL.

 

[dmaziuk]

https://i.ytimg.com/vi/SIMzRX3EuBg/maxresdefault.jpg

Edge retention: meh
Rust proofing: meh
@ $1.98: priceless