Concerning the Lunocet


Over the past couple of years curiosity andspeculation about the Lunocet has undulated its way to a near-feveredbreach.  Claims and counter-claims,random wishful guesses, pessimism, optimism, incredulity and all manner oflunophrenia hath poured forth.

Well, I’m here to tell ya; I’ve tried it -and for more than just a splash.  So haveEric Fattah, Peter Scott and Will Trubridge.

Lunocet 5

We’ve got the straight poop, the good oil,the upshot and the skinny and we’re servin’ it up hot, wet and in-your-face.

But first I’d like to set the recordstraight. I’ve spoken extensively with the inventor, Ted Ciamillo, and he’sbeen very clear about what the Lunocet is designed to do.  The Lunocet is designed to enable a humanbeing to breach out of the water under its own power.  That’s it.  Anything else it is good at is icing on thebreach.

As freedivers we inevitably brought acertain bias to our tests.  There arethings we expect from a monofin that are purely a function of our experienceand priorities as freedivers. Efficiency, for us, is defined as distance covered with energyexpended. 

The Lunocet is designed to transmit anexplosive burst of energy into enough acceleration in a very short distance tolaunch you out of the water.  Enduranceis not really part of its design equation. 

We were all hoping the twain would meet.

Next – I’d like to thank Ted for gettingthis unit to me in time for the Blue Hole trip, and for his infinite patienceand guidance in the fine art of drilling out the titanium screw I managed tosheer off in a frenzy of unnecessary disassembly. 

Ted, if you ever decide to get out of theinventing game, you’ve got a rewarding future in tech support.


The Lunocet is incredibly light, well builtand cool looking.  Take out one screw andyou can fold it in half and stick in a brief case.  It’s light enough to strap to a backpack ortake along on a bike trip. 

The Lunocet human interface is a pair ofcycling shoes mounted to the footplate on the fin.

Ithas tensioning screws in each axel mount that allow you to adjust tension onthe silicone membrane that runs along the trailing edges of the foils andbetween them.  This is a clever way ofgetting the fin to store some energy as well as filling surface area gaps.  Tweaking the tensioners allows you to varystroke amplitude – sort of like having a soft through hard monofin all in one.

Lunocet 1

After the screw debacle, and the day beforeI left for the Blue Hole, I took the Lunocet down to West Grand Traverse Bayfor a maiden run.  The water was 43F(6c)and choppy, with air temps around 24F(-4c) and spotty blizzards blowing in outof the north.

Not wanting 43F water shooting up mywetsuit top, I opted for mainly horizontal swimming.  I tried Ted’s advice of a wider amplitudeswim style and found it predictably inefficient in the horizontaldimension.  But with good monofin formthe Lunocet felt surprisingly solid. 

I seemed to be cruising along at a goodclip and the fin was completely quiet in the water. However I was getting tiredfast, and my dive buddy had no problem keeping up with his C4 30s on thesurface. At depth I was hard pressed to catch him when he was cruisingcasually.

By contrast,with my hyperfin I can both outdistance and outlast him.

I swam about a mile, mostly underwater. Itwas cold and rough. I did a little sub-surfing on the way in and the Luno’shigh oscillation rate worked out nicely in the shallows. Needless to say, myfeet were warm and comfy.

Afterward we discussed the session.  Jason, my intrepid dive buddy, felt theLunocet was doing an optimistic 2/3 of my hyperfin cruise speed.  I felt it was doing it with about 50% moreeffort but it was too early to judge. 

Inthe Hole with the Big guns

FYI – There’s none of that anxiety thatcomes with flying with a monofin with the Lunocet.  It would take a rabid TSA agent with an MP5to damage the thing.

I took it into the Blue Hole that firstmorning and was immediately accepted by the Tarpon.

As the other divers arrived I explainedeverything Ted told me about it.  Notablythat it is a ‘completely different animal’ from a monofin and that we shouldapproach it in an unconditioned and open-minded way.

I’ve been diving exclusively with monofins,year-round, for a couple of years.  PeterScott is one of the pioneers in using monofins for recreational diving. He alsoteaches monofin technique and is probably the most efficient recreationalmonofin diver I’ve ever seen.  EricFattah is the other monofin pioneer and was the first freediver to set a worldrecord with a monofin. He brings an open mind and a finely tuned capacity foranalysis to anything he is checking out. I thought his particular constantballast technique would be well suited to the Lunocet.  William Trubridge is relatively new tomonofins, but has probably been deeper in constant ballast and farther indynamic with them than any of us.

Though each of us approached the Lunocet witha slightly different perspective and emphasis, our conclusions are inagreement.

The Horizontal

‘I can’t generate any momentum’

Far and away the most common remark aboutthe Lunocet was ‘no momentum’.  While theLunocet gives a nice return on each kick – particularly with large amplitude -but not shabby with low amp/high frequency either; it is fighting its own drag.

Forget about gliding. You’ve gotta stay on topof this thing to make it go and it burns energy fast.  Thrust is good, but does not approach that ofa good monofin except at very high amplitude with knee angles approaching 90degrees. 

No matter how we swam with it, compared to a monofinin horizontal swimming, the Lunocet covered less distance in more time withmore energy expended.

If, as Ted asserts, the Lunocet has lessdrag with high oscillation than a conventional fin, we did not see thisreflected in raw performance – even under full tension. (I did encounter aproblem with the blade not returning – one axel was sticking and making a creakingsound under full tension. I resolved it with a little silicone gel beforeanyone else tried it).

Lunocet 4

The Vertical

I was pretty geeked to see what Eric Fattahthought of the Lunocet for FRC constant ballast.  I thought the nice bite it has with a bigkick might appeal to him.  We all tookturns running it up and down the lines.

I took it down to 81′. Pete and Eric eachtook it to 30 meters (98.4′) and I think Will did the same.  The Lunocet is very solid on the trip up ifyou go with a high amplitude stroke. On the way down it is miserable. You have to work hard to fight your way down and when you finally hitfree-fall you’ve got some serious drag to contend with.  I definitely spent more energy in my81′(24.6m) dive with the Lunocet than I did doing 119′(36.2m) in my hyperfin.Effort wise it was pretty close to the same as my 86′(26.2m) no fins dive – andmy no fins technique was all of 3 hours old. Most of  the energy expended wasdefinitely on the way down. 

The Lunocet is quite buoyant, as Eric F. pointedout in his DB post: “The buoyant natureof the fin is excellent for vertical stability during the sink phase, butcreates some annoyance during horizontal hangs at recreational depths, whenyour feet start floating towards the surface, and you end up ascending feetfirst.”

And: “Anotherbenefit of the Lunocet is the low mass and zero buoyancy change. However thehigh drag overwhelms those advantages, in my opinion.”

Eric and Pete both did kick-counts. Ericdid 11 strokes up from 30m.  Pete did 5from 15 meters – same as his hyperfin using the same kick style. 

That doesn’t tell the whole story, but itdoes point to the fact that the Lunocet is not bad at what its builtfor – accelerating fast against gravity and drag.


It was during our vertical tests that Iexecuted the following maneuver:

I kicked up and planted both hands on theraft, then spun to sit. Pete and I looked on in horror as my left lower legsnapped back into place. 

The Lunocet, with its rigid foils andunyielding foot mount, is a bit like strapping yourself into a pair of downhillskis with no quick release binding.  Anyrotational force goes straight to your knees.  In heavy currents or surf, where you may be unableto quickly haul your legs in so the Lunocet slices sideways through the waterwith the force, you could have a very serious problem.

Thisexperience curtailed any further testing by me or Pete – who is about two yearsout from knee surgery – and shot down my ideas about the Lunocet being greatfor sub-surfing and river running (that’s right – you get a river that isrunning high, ideally with salmon spawning in it, and haul ass down stream).

Alaspoor Breach, I knew him not.

Regrettably the knee situation curtailedour breach assessment. We wanted to wait until we had a good sense of how thefin worked before we got into breaching and the torque issue hit me just when Iwas ready.

Eric did try to breach with it, but foundit wanting compared with his Chen Bin.  Ihad similar results with my casual attempts but I think breaching requires somespecific adaptations, which is why I wanted to approach it systematically.

I can’t speak authoritatively, but I’mpretty confident the Lunocet is indeed well-optimized for breaching. Thetechnique will be different than with a mono, but I could definitely feel it onthe way up.  It bites right into thewater and gives you a good platform to spring from.



“..I was not able to swim fast with the device.”


The Lunocet, in its current form, is notcompetitive with a decent monofin for recreational freediving.  It requires too much energy to drive and itsperformance in terms of speed is mediocre, regardless of frequency or amplitudeof kick style. If you are familiar with monofins you know that the first fewkicks accelerate you into a hydrodynamic groove that enables efficientcruise.  With the Lunocet you are prettymuch always in that initial acceleration curve. It gets a little better with high frequency/low amp undulation but themonofin still wins easily.  To me theLunocet felt fast. I was alwayssurprised by how little distance I’d actually covered.



“Pete and I looked on in horror as my lower left legsnapped back into place..”

The knee-shearing problem is, in my view,very serious.  It’s a deal breaker fortwo applications I think would be an absolute blast with the Lunocet; Sub-surfing and River- Running.


(DISCLAIMER: I take absolutely noresponsibility for the consequences to anyone who is gonzo enough to actuallytry river running – I’ve done it, it’s a scream, you might die.)


I’ve run every last bit of this by TedCiamillo, and he’s there for all of it.


During a recent conversation Ted explainedhis perspective regarding the drag we all noted with the Lunocet, and the stepshe is taking to correct it. Specifically, he pointed out that what is going on may in part be aturbulence-induced disruption of the thrust generated by the Lunate design.  This explains what we experienced better thansimple drag.


While the iteration of the Lunocet wetested requires too much energy input to be useful for freediving, it isevolving as we speak and in direct response to the input in this article.


Ted is definitely walkin’ the walk when itcomes to dedication and willingness to accept criticism. If he succeeds incleaning up the drag on this bad boy …..!

Lunocet 3



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