Halcyon has built a solid reputation for making top-of-the-line gear, primarily for technical divers. All of their gear is built around the standard technical setup of wing and backplate BCD, rather than a typical jacket BCD.

Very often, divers using this kind of a BCD setup will opt for putting their knives on the waist belt, very similar to the way you’d carry a normal knife in your belt. The advantage of placing it here, is that the risk of the knife itself getting tangled up in something is minimal, and the knife can easily be reached with both hands, almost regardless of which part of your body is entangled. Knives to be placed here will need a sheath that accommodates being threaded onto the belt.

Halcyon makes two knives, both of which are made for this specific way of carrying them, both of them made in titanium. The H model is a traditionally designed knife, though smaller than most dive knives. The Explorer model, however, is even more minimalist. It consists of a single piece of 5.75” titanium, which makes up both blade and handle. This makes its profile beyond slim, and reduces the weight to 2.2 oz. Titanium is chosen, as it is both lightweight and corrosion resistant. The blade itself is 2.5”, making this one of the smaller knives on the market.

To further reduce the profile of the knife while sheathed, Halcyon has elected to omit the traditional closure system that locks the knife in place in the sheath. On their H model, this was done with a nylon strap with velcro closure, which is already a more minimalist solution than the integrated locking systems many knives feature. But on the Explorer, it is removed all together, with the friction between the blade and the simple nylon sheath holding the knife in place. This means that the entire thing (knife and sheath) weighs in at only 2.2 oz, and measures only .12” in thickness at the thickest point.

Tech specs

  • Material: Titanium
  • Length (overall): 5.75”
  • Length (blade): 2.5”
  • Weight (knife and sheath): 2.2 oz
  • Edge type: Smooth and serrated
  • Including line hook: Yes
  • Sheath material: Nylon
  • Attachment type: Belt loop
  • Attachments for BCD: No
  • Attachments for low-pressure inflator hose: No
  • Attachments for leg/arm: No

One feature that seems fairly inconsequential, but that I’ve actually come to appreciate about the knife, is the slanted sheath design. The knife sits at about a 50° angle (from horizontal), designed to make it easier to reach the knife when placed opposite the diver’s dominant hand. So right-handed divers would place this knife on the left side of their body, while left-handed divers would put the knife on the right side. While a small slant might seem of little importance, I was actually very impressed with how much easier it made deploying and replacing the knife.

While I had some hesitations as to whether or not the knife would stay in place during a dive, I put it through the ropes during a recent wreck dive, where I found myself in pretty much every angle imaginable (including completely inverted upside-down), and it never budges. The combination of the friction and the negligible weight of the knife, means that the knife isn’t pulled from the sheath by gravity.

No doubt the diminutive size and minimalistic design of the knife will put some people off from it, but as anyone reading my articles on dive knives will know, I’m a big proponent of small knives. I like that I have a knife I can put on my gear and forget is there until I need it. And this one definitely fit the bill. It is small, lightweight, and so slim that you can literally forget that it’s there. You don’t even have to worry about rinsing it after diving, as the titanium won’t corrode. And if you’re a travelling diver, counting every ounce, this knife will definitely not weigh you down!

It rest fairly well in the hand, though for my size hand (I’m a fairly average sized guy) it felt a little small to get a really good grasp of it, in particular if you need to cut through a tough material. Cutting through fishing lines and nets were a breeze, as the blade is very sharp, and maintains its edge well. Getting it out of the sheath and replacing it is easy, helped by the angle mentioned earlier.

The design of the simple sheath means that it is pretty much only suited for carrying in the belt of a tech wing BCD. There’s no real way of attaching it to neither leg, jacket BCD, or on the low-pressure inflator hose.


8ScubaDiverLife score

Halcyon Explorer Knife

Extremely lightweight
Corrosion resistant
Titanium maintains edge sharpness well
Small and compact

Titanium is hard to sharpen yourself
No attachment option for legs, arms, BCD.
No optimal for jacket BCD (intended for tech BCD)
Hard to grip with thick gloves

All in all, the Explorer is an excellent knife for travelers and for people (like me) who isn’t a fan of large dive knives. For anyone who regularly use their knives to cut through serious stuff, such as marine rope for cleanup purposes, say, will probably find it lacking. Personally, I probably wouldn’t take it with me for kelp diving, but for the absolute majority of the dives I do, it is a great choice.