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There are many different things you can do while scuba diving but regardless of whether you like to ica dive pr simply want to take nice tropical fish pictures you will find a dive knife a very good and helpful accessory. Ghost nets and other objects can be dangerous if you get entangled in them and having a knife with you that can help you free yourself is therefore highly recommended. When taking tropical fish pictures you may for instance become so absorbed by your task that you don’t notice that large ghost net stuck on the outside of the ship wreck where the most spectacular lionfishes are playing peek-a-boo with your camera. In such a situation a good dive knife will help you free yourself from the net before things get critical.
The two most important things to think about when buying a scuba knife are:
- Make sure that you get a scuba knife that is right for you and your diving style.
- Make sure that you know how to use the kind of dive knife you choose to get. A sharp knife in the hands of an insufficiently prepared diver can cause more damage than what it prevents; especially in a panicky situation.
In this blog post we will take a closer look at the first point choosing a dive knife.
What size should the knife be
Generally speaking, dive knives can be divided into three size groups: standard size knives, mini knives, and big knives. The standard size is 4-6 inches (10-15cm) and a standard size knive can be comfortable mounted on your arm or leg. An import aspect to consider is making sure that the handle is big enough to fit well in your hand. A mini knife will have a 2-3 inch or 5-7.5 cm blade and can for instance be worn clamped onto a hose due to its petite size. They can however be hard to use wearing gloves due to their small size. It is therefore extra important to try the handle on a mini knife before buying it. Any knife with a blade that is longer than 6 inches (15cm) is ti be considered big and can though to handle with any degree of precision under water. You should only get a big knife if you do something underwater that really requires a big knife, otherwise a small knife is to be preferred.
What material should the knife be made from
Most dive knifes are made from titanium or stainless steel. Titanium knives are the best most durable choice but it is also to most expensive option to buy, they can howeverbe cheaper in the long run as they last a lot longer than steel alternatives. A stainless steel knife will on the other hand be more susceptible to rust and corrosion, but you can counteract this by rinsing it off in freshwater after each dive and leave it to dry completely before putting it back in its sheath. It is a good idea to coat it with oil or silica.
Serrated edge or not?
Depends on what you want to cut, a straight edge is better for cutting artificial material like nylon while a serrated edge is better for cutting natural fibers. If you decide to go for a serrated knife, ideally pick one where the serrations run almost the entire length of the blade to make it possible to get a nice sawing motion going when you need to cut something. Today, you can also find multi-purpose dive knives where both types of edging is present on the same knife.
Sharp tip or not?
Sharp tips are popular among spear fishers, but if you plan on using your knife for something else then a blunt tip is usually to be preferred. A sharp tip will easily break if you try to use your knife to hack, chisel, pry, dig or similar. A blunt tip is a lot less likely to end up damaging your scuba gear than a sharp tipped one.
Do I need a line cutting notch?
Yes, I would recommend getting a dive knife with a line cutting notch since it can come in handy if you ever need to cut a small line.