Brace yourself, this will probably end up being a long article.  If you have a sense of humor, can appreciate brutal honesty, and can tolerate flashbacks inserted for understanding of current events then you might enjoy my write up.

Special thanks to Randy Thornton, Lauren Kieren, Jon Kieren, Michael Blake Thornton, Wayne Kinard, and all the others that I missed.

I recently did a dive with some guys to get some video for manufacturer promotions.  At this time, I being the sneaky little bastard that I am, was able to get a look at some of the bits and bobs of a Hammerhead rebreather as it was being put together.  I saw a couple of things that seemed really well thought out and impressed me.  I decided right then and there that I needed to reach out to a Hammerhead diver to get a better look.  I just so happen to know a guy that has been more than willing to talk to me and show his unit (not that unit, stop thinking dirty), but I never got around to calling him up yet.

Suddenly SubGravity decides to have a demo day a few hours north of me.  Obviously this really got my attention, but I was not willing to become a traitor to my rEvo just yet.  My buddies would have burned me at the stake.  I read about the demo site and found multiple reasons for me to go.  I had never been to Blue Grotto, there is a cave there, several people I knew would be there (of my many many fans), SubGravity would have many of their products there for demo, and it was within driving distance for me.  I finally bit the bullet and signed up just short of the last minute, in an effort to keep myself from being verbally assaulted too badly.

Many will remember my anti-hammerhead rants in the past, but please know that my references were aimed at juergenson marine electronics rather than Hammerhead rebreathers.  I have since been very careful to differentiate between the two and out of respect for Randy have toned down my rants.  Needless to say, getting me to do anything Hammerhead is a huge accomplishment for SubGravity to accomplish. At least I showed up with my trusty rEvo to even the odds a little bit.

The day began with a quick orientation of how the day’s events were going to be organized and a basic introduction to the SubGravity demo products.  Basically there were three events, DPV demos, rebreather demos, and guided cave dives.  They also had some awesome dive computers for demo too.  We then broke into “event” groups to get fully briefed and proceeded with the day.

Randy had me suit up and help with DPV demos to start, until it was time for my cave dive.  I must say that there was a huge interest in the scooters.  They were constantly underwater and the divers were nothing but smiles afterwards.  It was a bit of a shame that the basin did not allow for a little more room to get a real ride on them though.  It might have been for the best with a diver that was new to such power.  I went full blast on the surface and it was reported that I caused a huge wake.

The cave can only be entered with a guide.  This is to make sure the cave is not trashed by skill challenged divers, or any other idiots for that matter.  Our guide had an equipment issue, and since one in our group was a cave instructor, we were allowed to go on our own.  I must admit how privileged I felt by his trust.  When he asked who was going to lead, my first instinct was to scream “ME”, but I resisted.  Nobody said anything until I finally volunteered.  I know that this is not a virgin cave and I was not running any line, but I certainly felt empowered and fortunate to lead this dive.  Although the cave is not very big, it is still almost entirely perfect and natural.  It was an awesome experience and I am glad to have been able to do it.  

Up next, my big event, and what everyone was dying to witness.  My demo of a Hammerhead rebreather.  I was extremely happy to know that all of the supplied units had the back mounted counterlungs.  I felt this would give me a better comparison on work of breathing versus my rEvo.  There was a brief rundown of the unit and a short Q&A before getting geared up and in the water.  When I stood up, my first question was how much does this thing weigh?  It was so nice to have such a light thing on my back.  I was a bit shocked to be able to notice a difference.  My main goal was to compare work of breathing.  When we were finally in the water, I realized instantly that I was way too light to sink with my heavy undergarments.  There was no way that I was going to miss this opportunity and pulled myself down one of the buoy lines.  I was forced to keep my suit a bit overly squeezed but I tolerated it.  Initially I found everything very comfortable and easy.  It was only then that I realized that my trim was spot on perfect without any effort what so ever.  It just happened.  I extended my arms and legs, wiggled around to check stability, and instantly popped back into perfect trim.  My buddies will probably tell me that is was some form of black magic since that is all that could ever fix my trim, but obviously I need new buddies.  I rolled to my side, my other side, head up, head down, and finally over on my back.  It was when I was on my back that I had a wakeup call, I was so much more stable in the water than with my rEvo.  My position in the water column was remaining almost constant without any effort on my part.  Up to this point the work of breathing has been far superior to anything I have experienced on any other rebreather and I am referring to any position I could put it in.  I decided to exert myself and check further.  I began breathing very shallower until I could feel the CO2 building and grabbed a log for support.  I began kicking for all I was worth until I was breathing hard and I could feel my heart pumping good.  The heavy breathing was still easy and I could find no faults with how quickly my breathing resumed to normal.  I have never used a BOV and got to play with one now.  These things do make BO pretty damn easy and quick.  I am still not sure I like the bulk though.

I got to look at the demo dive computers but never got one in the water.  They are small, size of a watch, with a highly visible screen.  They seemed like a great little computer with big abilities.

Now for the final verdict:
Other than items of mere personal preference or what I am used to on my rEvo, the only fault that I could possibly come up with was something that I noticed in the configuration during the briefing.  I will not even mention it because SubGravity was aware of it have already implemented the change.  The trim, buoyancy, and work of breathing completely blow my rEvo away.  It really kills me to admit it, but it is true.  I know that you can get any rebreather to trim if you work at it, but the Hammerhead already has the sweet spot right out of the box.

The way they have the new electronics setup now allow simple plug and play and never needing to ship the head in for repair, just unplug a handset and send it in.  Serious insight and design went into the new connectors and even the internal components are plug and play bits.

The use of bayonet fitting throughout the unit makes it almost completely tool less.  Anything needing a tool is rather major and can still be done by the average user without much concern or fear.

Randy took the time to walk me through the new electronics for both the Hammerhead and XCCR.  I was thoroughly impressed with them.  They have a screen that is as visible as my Predators (I am still a diehard Shearwater fan).  There are a couple of new functions available too.  One of the big things is that the sensitivity of the piezo switches is adjustable.  How cool is that?  There is a setting to adjust the alarm for the CO2%.  Tank pressure on the handset.

One highlight of one of the handsets is that the battery is a rechargeable one and it is sealed in the handset.  It is charged via an inductive method.  It is not user changeable, BUT it is a simple thing for the SubGravity guys to replace it when/if ever needed.  I was skeptical when I heard it was not user changeable and asked about this.  I did not want to see another episode like the circus the X1 created.


NO – I am not selling my rEvo to buy a Hammerhead, unless someone want to give me $10k for an 8 year old rEvo.

YES – If I were to buy a new rebreather today, the Hammerhead is the current top contender


SubGravity Demo Day