The Megalodon is made by Inner Space Systems, and is the brainchild of ISC owner and CEO Leon Scamahorn. I first got a chance to see the Megalodon on the Nautilus Explorer after a friend had bought one, and I was very impressed. It is a very serious looking unit and has a distinctively hand-made, one-off feel to it.
Unlike the other units I evaluated, the Meg is completely modular. There there are some standard configurations, but in the end, nearly everything is an optional addon to the basic envelope. It is built on the foundation of the outer housing, which is essentially an aluminum cylinder containing the standard axial scrubber, oxygen cells and electronics package. Two nice displays are attached to the head, as well as an optional HUD. Since the outer housing is constructed of aluminum, it is very rigid, giving you a number of options when it comes to attaching your oxygen and diluent bottles. The one I like best is the Tiger Gear setup, whitch provides a very elegant and tough mount.
The hoses, ADV and front-mounted counterlungs are all extremely well made, and the design on the unit gives it a very low profile. Leon spent 12 years with the Army Special Forces and it’s clear that he has built the unit with his military background in mind. The first thought that comes to mind when you see the Megalodon is that it is both incredibly rugged, and user friendly. The displays are large and easy to read, and apparently they tested the resiliency of the unit by dropping it from five feet onto a concrete floor. When a component broke, it was made stronger. When they were all done, the Meg was fine, but the concrete floor was broken. Did I mention that this unit is built to be tough?
The ISC website has a really nice breakdown of the Meg.
The list of things I like about the Megalodon is fairly long and detailed, but I’ll try to sum it up as best as I can:
- Solid construction
- High quality materials – Alluminum, ballistic nylon, acetal, etc.
- Water traps EVERYWHERE
- Corrosion resistant
- Easily readable handsets
- Low porfile
- No housing / shell nonsense
- Batteries sealed off from the breathing loop
- Modular design – Mount any cylinders, use any backplate / wing.
- Ability to use any scrubber you like – Megalodon, CisLunar, Extendair, and an SMI Prism.
There aren’t really many things I don’t like about the meg, but there are a few points I think might make it a little better.
- I wish it had a radial scrubber. While you can use the CisLunar or SMI Prism scrubbers, you have to purchase these seperately if you can find them.
- While the electronics package is great, it is only a loop controller. I wish the unit had the ability to do integrated deco calculations. This feature is coming in the next version of the software, but I would imagine that it will be a costly upgrade.
- I would like to see a slightly more readable HUD. It is only one LED that blinks codes for each sensor. This is fine once you get used to it, but the SMI Prism has a slightly better HUD in my opinion.
That’s about it. Like I said, these aren’t really complaints, but more of a wish list. The Meg is, after all, the unit I decided to get for myself.
The following are the additional options that I decided to get on my Meg:
- ADV (Automatic Diluent valve)
- HUD
- Mixed Gas Bypass – A must for TRIMIX, it provides the option to plumb in off-board gases
- Faber 20cf Steel bottles
- Stainless Steel back plate with continuous loop harness
- Drive Rite Aircel TREK wing
As I believe it will result in a system that runs with much less moisture, I have every intention of trying to find a CisLunar radial scrubber at some point. This is by far, the most advanced scrubber design ever seen in the world of rebreathers. For the time being, however, the standard ISC Axial scrubber should be just fine.
Rebreather Evaluation – Part 3: The PRISM Topaz >
Rebreather Evaluation – Part 5: My Decision >

[...] Rebreather Evaluation – Part 2: The Inspiration > Rebreather Evaluation – Part 4: The Megalodon > [...]
Shoulda just built your own rebreather: http://www.atlimp.com/pend2.htm
[...] Rebreather Evaluation – Part 4: The Megalodon > [...]
Sir/Mam,
I was reading the article” Rebreather Evaluation – Part 4: The Megalodon” dated Jan 24, 2006.
It would be nice to have a ~3 year followup on the author’s experiences after buying the Meglodon. Does Cliff still write for you?
Thanks,
Jim Bogart
http://spiralbound.net/2006/02/24/rebreather-evaluation-part-4-the-megalodon