The life-cycle of a diving knife

[chrisch]

....
I think @Shotmaster 's reply sums up one of the biggest reasons to carry a more substantial tool. Yes a line cutter and shears will cover 99% of normal cutting tasks, ...

Shears would easily cut netting. I cannot actually think of any reason you would want a large knife. If strapped to a leg it is an entanglement hazard in itself and more harm than good. Cutting rope off a prop is one reason to have a large and robust cutting tool available, but the best thing for this task IMHO is a hacksaw blade. Either way store it on the boat in the dry and it will last a lifetime.

 

[Storker]

I cannot actually think of any reason you would want a large knife

Harvesting/hunting has been mentioned a couple of times already.

Even if you personally don't see any reason to carry something bigger than the GUE-approved mini knife, that doesn't mean that no-one else can see a reason for that either. Use what's appropriate for your needs and let others use what they find appropriate for theirs.

If strapped to a leg it is an entanglement hazard in itself and more harm than good

How big is that risk provided you strap it on the inside of the calf - AFAIK what's recommended these days? I do that and I've never had an issue with it.

 

[Skulmoski]

Benchmade 7 Rescue Hook (right BCD shoulder strap)
Spyderco FB31SYL Enuff Sheepfoot Fixed 2.75" H1 Serrated Blade (BCD waist belt, left side)

A bit of silicone grease after they are thoroughly dried.

GJS

 

[Fin Finder]

In our area most of the wrecks have a fair amount of old monofilament fishing line snagged on them. I have had to cut myself free of it a couple times, but that’s the only time I’ve ever had to use a knife U/W. I always carry two cutting tools, located at two different points on my body, so I have a better chance of getting to at least one of them if I’m tangled. My usual cutting devices are a trilobyte in a sheath bungied to my left wrist with my computer, and a folding knife in a sheath on my BP’s waistband.

I’ve never gone in for expensive dive knifes. I only buy the cheap $10 ones at the sporting good store. I buy two or three at a time and replace them when they get rusty. If a cheap knife drops out of my hand on a dive, I don’t risk injury trying to retrieve it. The folding knives with the large unlock button on the top of the handle work best with dive gloves. Something with around a 4” blade is enough for me.

I have found several expensive lost dive knives on my dives. Usually titanium. I’ve also found a few sheaths without knives. The last time I inquired, the manufacturer would not sell me only a sheath, so for diving they’re now useless. It’s a shame. If the owners had scratched or painted a phone number on the handle they would have gotten them back.

On a dive boat I once saw a young guy, probably a new diver, with a knife strapped to his leg with a blade that was at least twelve inches long. It looked like a samurai sword. Kinda funny, but I'm sure he liked how it looked on him.

 

[tarponchik]

I have a Spiderco folder. I often use it as a tool/kitchen knife during the dive trips but so far never used it underwater. I hope I'll never have to but I know it is there if I need it.

 

[Eric Sedletzky]

I've actually lost almost every click lock style knife I ever had. Plastic buttons and plastic spring loaded gizmos to keep knives secure eventually all fail. The only way I found to positively secure any knife is some sort of sheath that has the knife bungeed in or a well secured cover, or a well made sheath that pressure fits around the knife. All these options seem to always be home made or home modified in some way. I dont know why the manufacturers cant come up with something that wont fail. Plastic is not a permanent and durable solution.
Also, I found anything made out of 304 as a cutting device is pretty worthless. It is impossible to obtain a super sharp edge on 304 and worse to try and keep an already mediocre edge sharp. The only thing I found that works well for cutting is 400 series stainless.
The BFK I have that I use for scallops is 304 but I only use it for a prying tool and to slip into the shell to cut loose one side of the scallop meat to get the shell open. Some of those shells get 8" - 9" in diameter so a knife that big is a bonus otherwise you couldn't reach in that far to cut loose the meat. However for a cutting device for line and such that knife is worthless.

 

[JamesBon92007]

Sometime back in the 80s I started hearing about not wearing your knife on your calf because of the entanglement hazard. I dive mainly Southern California and have been in a lot of kelp and it never even got snagged. To me this supposed hazard is a projection of someone's fears. Or maybe because I know it's there I avoid the kelp. The reason I keep it there is so I can get at it quickly and easily in case I get in a knife fight or need to fend off a shark or some unimaginable sea monster. But, like I said, that has not happened yet. Besides, it looks really cool strapped to my leg. Anyone who doesn't think it's cool has leg-knife phobias.

I tried putting in on my weight belt like Mike Nelson but it was uncomfortable and awkward. I figure he just hadn't thought of leg straps yet.

I think I paid about $8 for my knife originally. I also have a couple of spare knives and sheaths like the one Shotmaster posted a picture of with the blunt head which looks like it would be great for tenderizing abalone. When I bought my knife I opted for the one with a D-Ring where I could put a wrist strap to keep from losing my knife. It seems to have paid off.

To care for it I simply rinse it in fresh water outside of the sheath and don't put it back until completely dry. Occasionally I'll remove the handle but it doesn't really seem necessary.

 

[Brandon]

Victorinox makes a number of inexpensive stainless steel knives that are considered standard issue for commercial fishermen. They make damn fine dive knives and are all of $20 for the knife and the sheath. Will zip through any line you're likely to come across.

 

[Eric Sedletzky]

Victorinox makes a number of inexpensive stainless steel knives that are considered standard issue for commercial fishermen. They make damn fine dive knives and are all of $20 for the knife and the sheath. Will zip through any line you're likely to come across.

View attachment 374978

This is the one I was talking about in one of my above posts. I couldn't remember the name. The ones I get have a red handle and are even cheaper than the one you linked, but the blade looks similar and is probably made from the same material.
They don't come with a sheath either.
Those things cut through anything like butter.

 

[Storker]

Looks OK if cutting line is all you're going to use the knife for.