But really, I was in Grand Cayman to complete a training program on the Megalodon and Pathfinder rebreathers. You can ask Emma or Nancy, I was in class each morning and diving in the afternoon…you know skills, drills and well ok, some fish, corals and steel; one dive was on the Kittywake.
While I have a lot of experience diving the Megalodon rebreather, the real treat of this trip was to dive the Pathfinder in something other than the pool. Not that I mind the pool, but there is something more interesting about a vertical wall with fish, colourful corals and vibrant sponges. Remember, part of my training was swimming in the unit.
The unit can be configured with a standard over the shoulder set of counterlungs or with the new top of the shoulder counter lungs. One of the other configuration options is the diliuent bottle. You can configure it like a standard rebreather with the diliuent and oxygen supplies mounted to the canister or, alternatively, you can utilize the bailout cylinder as the diliuent thereby reducing the weight and simplifying the rig for the diver.
Unlike some of the other rebreather designs for more recreational divers which try to minimize any diver thought or input into the system, the Pathfinder is designed for a thinking diver. Since you can never fully factor out the human interface, Leon Scamahorn, designer of the system, believes that the diver should be included and involved in the system. This does not mean that the system is complicated but rather it needs some input from the diver during the set-up and initialization phases of the dive. Further, it offers the diver more options in dive parameters and uses.
While a purely “recreational” diver will love this unit, the Pathfinder is capable of mneung beyond what we normally consider to be recreational diving. Leon designed the unit to have enough scrubber media and system capabilities for a diver to do a typical normoxic trimix dive (using helium in the breathing mix.)
So you are probably asking what did I think about it? It was a real treat to dive a lightweight but capable rebreather. The work-of-breathing, a performance measurement, is similar to that found in the Megalodon rebreather. What this means is that it is easy to breath in the horizontal position as well as upside down and while facing up at the surface. The electronics are straight forward and easy to understand both on the surface and underwater and they do a good job of controlling the oxygen set-point or level. I found the unit trimmed well so it was easy to swim with in the water and because of its size and weight it was easy to exit the water. The scrubber packs easily and the assembly is easy and straight forward. It flushes easily and takes minimal amount of time to correct the oxygen levels.
