A knife is a very personal item. Even if you are issued one, many people will still buy one more to their liking. There are attachment options for just about every knife, but where is the best place to mount it? Again, that is personal; some people like it on the inside of their leg, some want it on their waste, and others like it mounted on their chest/ shoulder area. Here are my two cents about it. I like my knife high on my waist or left shoulder (because I am a righty, and it keeps my right shoulder pocked free for a weapon). A knife is a tool; if I need to use it, there is a good reason for me to grab it. If it is on my leg, I might not be able to reach it. If it is on my waste or above, no matter what, I should be able to get to it. Basically, you should keep a tourniquet on your waste for the same reason. I like having my knife there also.
Leg-mounted knives, which connect to your lower leg above your ankle and can be a convenient solution to keep your knife out of the way, are the most common on the market. However, keeping your knife far from your hands can make it challenging to locate or even reach an entanglement. If you miss the housing or do not activate the locking mechanism properly, stretching to place a sharp knife back into its housing can be deadly. Mounting your knife on your leg can be a snag hazard.
Some knives also tend to rattle in their sheaths, which can be fixed with a well-placed rubber band. There is also the thought that if it is on one leg, you will focus on that, and it can throw you off when you are navigating by making you focus on that side and push you left or right depending on where it is mounted. Most people tend to put them on the inside of their legs to help avoid snags. Some companies also make neoprene sheaths so knives can be mounted on your legs. Most tend to advertise that they are universal.
Some buoyancy compensator devices (BCD) have holes, especially for attaching your knife. Knife grommets and specialized locations to stick your knife, often under your arm above your pocket, are becoming more common. There are a lot of knife sheaths that are designed around being able to use this hole. They are great because it permanently attaches to your BCD, ensuring that you have it with you on every dive, and you don’t have to put it on and take it off for every dive. These mounts are unobtrusive and unlikely to snag. One bad thing is that because it is always there, some people forget to clean their knives properly after every use. What I like to do is soak my BCD with the knife on it and then take the knife off and dry it by itself with my mask and computer. I like keeping them all together. Another possible downside is you pack your BCD to travel, and when you get to where you are going, they pull you aside and take your knife away from you because you forgot you couldn’t take a knife with you, and yes, you can’t take a knife with you everywhere you go. So, keep that in mind also to never forget it is there.
I have seen divers with dive knives mounted on their right shoulder straps or BCD inflator hoses. These are handy in an emergency. When you keep your knife on your upper body, you’re more likely to be able to reach it in an emergency and safely replace it. I also like to have a hook-type knife on my waistband.
I know a lot of people that always must have that pointy knife. I have never really been that guy that thinks he will get a knife kill, whether it is of something or someone underwater or not. Point knives do more harm than good on a boat, especially a Zodiac/ Wing or an RHIB. I have seen my share of people cut their hands, head, or boat when they are just trying to cut the zip-tie off the front of a boat. So, be careful when using your knife. I will leave talking about knives to another time as I am sure there are some great opinions about what brand is best and why all other knives suck.
