The most notable priority of having a knife underwater is getting you out of a trouble, not attacking seaborne villains
Unless you are a special team under the sea fighter, whose sole job you should trace and exterminate the enemy positioning a bomb under your aircraft carrier, then the get knife is merely a device to get you free from the tight grip, if there is one. diving knife
Last year, a group of scuba risked a risky business of freeing a submerged fish trawler from their own nets. The ship sunk not far from Catalina Island, California, and rested on the bottom level wrapped in its own fishing nets, which became a deadly trap for oceanic creatures. Enthusiastic scuba used their knives for cutting the net and freeing the trapped sea poor things.
Diving is a risky business itself, not to mention the wreck snorkeling. Going some hundred toes underwater to pick up a combat artifact from a sunken trireme can be a deadly business. What if your lower leg got stuck, say, in an angling net.
And then, exactly as for action movies, you take away your diving knife from the sheath, grasp it firmly by the deal with, and cut and found yourself free from the menacing trap. You gained.
So, for the to happen, you desire a good and reliable dive knife and an easily accessible sheath and location to stick it firmly on. Define your dominant hand and place the sheathing on the opposite leg. The sheath shall hold the blade securely and firmly, however your underwater cutting tool must be easily accessible, if needed.
It’s better for the blade to have both serrated and smooth edges, because sometimes you may need to either cut or found.
The next urgent action is the steel. Titanium blades are best of all; the 300 series alloy comes second best, as ti lasts almost for ever before and the maintenance near none. The alloy is rust-resistant, however, you will have to sharpen it over time of use.
Secure your sheath in an easily accessible place on the body and practice taking away surgery so as to do it calmly and simply in case of danger.
And remember that your cutting knife for diving is a tool, and not a weapon. So don’t buy a 10-inch cutlass, as it will prove heavy and hard to use. Buy the one with a 5-inch blade and a handle of the same length, and it will be the most practicable choice.