Selecting the right dive knife for you
You can choose from a variety of dive knives, ranging in material, size and features. Finding the right one for you is down to budget, what you will need it for but ultimately personal preference.
At a minimum, these are the basic requirements you should keep in mind when looking for a dive knife:
Your knife should be made from a solid metal such as stainless steel or titanium – If money is not an issue, we would recommend a titanium knife as this won't rust and will remain sharper for longer. If you do opt for a stainless steel one, remember the higher the number of the alloy the less rust resistant it will be. So 300 alloy will be less likely to rust than 400 alloy. The catch is that the lower the alloy will need to be sharpened more frequently.
Sharp & Serrated
Have both a sharp edge for cutting and a serrated edge for sawing – as mentioned earlier, a knife is not a weapon but a tool. The serrated edge may be more useful for sawing through obstacles such as rope.
Protective sheath or holder
This isn't just important for guarding you and your equipment against the blade, but it also provides a double function as it allows you to attach the knife to your person. There are myriad of sheath designs to accommodate for where you will carry the knife both for ease of access and so you have quick release. Traditionally, all divers would attach their knives to their thighs but with developments in technology, it is now possible to carry you knife on the inside of your calf, round your arm or attached to your weight belt or BCD. It really is down to personal preference so try a few different places and see where feels more comfortable and easiest for you.
Beyond these basic elements, optional features include:
In the interest of safety, all divers should consider buying a knife with a blunt tip. It is highly unlikely that you will needed a pointed blade unless spearfishing, and blunt knives are much safer as there is no chance of accidentally puncturing your equipment, or worse, yourself.
Again this is down to preference, but some divers prefer dive knives with metal handles. Not only are they are more solid, but the double as a useful tool for tapping on your cylinder in order to catch your buddy's attention. You can get separate accessories for that exact purpose but why not kill two birds with one stone.
The grip, like anything which you hold, must be comfortable to ensure you can use if efficiently. Especially in diving, say the worst case scenario of becoming tangles with little air remaining, accessing and using your knife efficiently may only save you a few seconds but can mean the difference between life and death.
Wreck divers and cave divers may want to carry a back up knife as they are more likely to use them, and therefore lose them. Wreck divers because there are a lot of dangerous areas on wrecks and therefore an increased possibility of becoming entangled or trapped. Cave diving because reduction in natural light may result in you dropping your knife and being unable to retrieve it.
Most dive knives are made from stainless steel but they still rust. To ensure your knife last you as long as possible there are easy small steps you can take to lengthen the lifespan of it. Rinse it in fresh water after you have taken on a dive, whether you used it or not it will still help in ridding it of salt water corrosion.
Secondly sharpen the knife as you would a regular kitchen knife. Most manufacturers will provide instructions when you purchase the knife to ensure how to maintain it.
Titanium knives, which are a purer material, will require less maintenance than stainless steel ones.
Check the sheath or holder before use, despite being made from heavy duty materials, excessive wear and tear may lead to damage or the knife coming lose and you don't want that mid-dive!