When it comes to scuba knives, two things are of imperative importance:

- Make sure that you get a scuba knife that is right for you and your diving style.

- Learn how to use it in a manner that is safe for you as well as for your dive buddies. If you don’t know how to use your dive knife correctly it can cause more bad than good.

Below you will find info on how to choose a knife that suits you.

Size matters

Generally speaking, dive knives can be divided into three size groups: standard size knives, mini knives, and big knives. A standard size dive knife, also known as medium size dive knife, has a 4-5 inch or 10-15 cm blade and is small enough to comfortably keep mounted on your leg, arm or BC. An import aspect to consider is making sure that the handle is big enough to fit well in your hand. Mini Knives are 2-3 inches (5-7.5 cm) and can be mounted on the air tube. 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. When scuba diving, big doesn’t automatically equals better so only get a big scuba knife if you know that you will be doing things underwater that actually require a big knife.

Material

Titanium and stainless steel are the two most common materials in dive knives. Titanium knives tend to be the most expensive choice, but are on the other hand extremely resilient to rust and other types of corrosion and a good titanium knife will stay sharp for numerous dives. 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. Coating it with a layer or oil or silicone is also recommended.

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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.

Should I choose a knife with a sharp tip?

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. The reason that a blunt top is usually better is that a sharp tip easily breaks when using the knife to dig and pry. Having a knife with a sharp tip will also increase the risk of accidently puncturing a BC your own or your dive buddy’s.

Do I need a line cutting notch?

Dive knifes should always have a cutting notch because that makes it much easier to cut small lines.

You should consider the following things before buying a dive knife

- Make sure that you get a scuba knife that is right for you and your diving style.

- Learn how to use it in a manner that is safe for you as well as for your dive buddies. If you don’t know how to use your dive knife correctly it can cause more bad than good.

In this blog post we will take a closer look at the first point choosing a dive knife.

What size should the knife be

There are three main sizes of dive knives, big knives, mini knives and standard sized knives. A standard size dive knife, also known as medium size dive knife, has a 4-5 inch or 10-15 cm blade and is small enough to comfortably keep mounted on your leg, arm or BC. 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. Always test the handle prior to purchase. Big dive knives have blades that are 5 in / 15 cm or longer and can be a tad cumbersome to handle underwater, especially for precision work. When scuba diving, big doesn’t automatically equals better so only get a big scuba knife if you know that you will be doing things underwater that actually require a big knife.

What material should the knife be made from

Titanium and stainless steel are the two most common materials in dive knives. 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?

A serrated edge is ideal for cutting natural fibres such as hemp ropes and kelp, while a straight edge will be more apt at cutting artificial materials like nylon ropes and monofilament fishing lines. 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. The best choice is usually a knife with a serrated edge on one said and a straight one on the other.

Sharp tip or not?

A blunt tip is to be preferred unless you plan to use the knife for spear fishing, spear fishers usually prefers sharp tips. A sharp tip will easily break if you try to use your knife to hack, chisel, pry, dig or similar. Having a knife with a sharp tip will also increase the risk of accidently puncturing a BC your own or your dive buddy’s.

Should I chose a knife with a cutting notch?

Dive knifes should always have a cutting notch because that makes it much easier to cut small lines.