A knife is a lot like a handgun, you don't need one at all until you need one real bad and right now.
When I started diving I carried a combination ab iron and dive knife that was about 15 inches long and weighted about a pound. It was trendy at the time.
Now I carry a combination dive knife and shears made by Parkway that functions well as a dive knife and yet will easily cut 1/8 steel cable if needed. It is better than most shears in this regard. This knife is normally mounted on the waist band.
I will also on occasion carry an old but very reliable and extremely sharp Scubapro stilletto dive knife in a very low profile custom sheath on my left fore arm. I will use this knife every now and then when collecting fishing lures in a river with a 4 kt current and the ability to use the knife while remaining streamlined and hanging onto something on the bottom is very important.
I tend to dive in limited visibility in areas with a lot of potential entanglements. Early in my career a local diver drowned about 6 inches under water due to an entanglement and I learned the importance of always having at least one knife in a location where it is accessible with either hand.
When I started diving I carried a combination ab iron and dive knife that was about 15 inches long and weighted about a pound. It was trendy at the time.
Now I carry a combination dive knife and shears made by Parkway that functions well as a dive knife and yet will easily cut 1/8 steel cable if needed. It is better than most shears in this regard. This knife is normally mounted on the waist band.
I will also on occasion carry an old but very reliable and extremely sharp Scubapro stilletto dive knife in a very low profile custom sheath on my left fore arm. I will use this knife every now and then when collecting fishing lures in a river with a 4 kt current and the ability to use the knife while remaining streamlined and hanging onto something on the bottom is very important.
I tend to dive in limited visibility in areas with a lot of potential entanglements. Early in my career a local diver drowned about 6 inches under water due to an entanglement and I learned the importance of always having at least one knife in a location where it is accessible with either hand.