Freedive Everest: First Ascent

By: Lance Lee Davis

The year 2020 blessed my diving buddies and me with good health, but any sort of destination travel was out of the question. Instead, we had to get creative in our local waters. It started when my friend, Benny, called me up in September and asked,

“Have you ever heard of Everesting?”

I had not. He explained that it was a challenge, particularly in the cycling and running community, where athletes—many of whom couldn’t compete or travel because of quarantine restrictions—would, in one day, run or cycle a route enough times to make a vertical climb equal to the height of Mount Everest.

“Oh, that’s an interesting idea,” I responded, just beginning to see where this was going. Benny continued,

“I checked, but to my knowledge, nobody’s ever done it freediving.”

On reflection, we calculated that I’d likely dove something close to that height—5.68 miles, or almost 30,000 feet—back in the day, during some spearfishing tournaments and island hunting trips, doing hundreds of drops to between 15M – 25M. Also, that’s if we count total distance traveled on the dive, meaning a 15M dive would count as 30M. This we judged fair, since freedivers work during both descent and ascent, unlike a cyclist who can stop pedaling and rest when coasting down a hill.

Planning it out

That amount of diving is certainly a huge day of work by any standard, but to a champion spearo or dedicated instructor, it’s not inconceivable. However, what if we were to do it in a series of hundred-foot (30.5M) dives?

Like, say, 150 x 100’ drops in a single day?

That would be extraordinary.

Special challenges abound

Muscle fatigue would be an obvious limiting factor for anyone, but here in southern California, we must also consider water temperature. Even in high-quality open cell wetsuits, that amount of time in the water is daunting. We dive, hunt, and train year-round off the coast of Los Angeles, but while a 5-hour session in late summer can be pleasant, a one-hour session in winter or early spring can get chilly. Thicker wetsuits would be warmer, but then there’s the actual physics of freediving—it takes more energy to move a heavy wetsuit around in the water column. You spend more effort to start the dive and then conjointly more energy to kick up from depth. To create that energy, the body requires more oxygen, and when coupled with growing fatigue, a hypoxic blackout becomes more likely. Blackout is always a concern with deep freediving, but a risk that trained freedivers know how to deal with. Having other trained divers to act as safeties throughout the day is non-negotiable while freediving.

Since the anticipated day would already be so taxing on the legs, I’d have to wear no more than the ‘standard’ southern California 5mm open cell wetsuit. A certain amount of leg fatigue would be natural for the amount of kicking required, but by doing 100’ drops, the depth itself would create a heavy anaerobic load on the legs, independent of the actual work of kicking for 5.68 miles. This is a phenomenon unique to freedive physiology and is a side effect of mammalian dive response. From my standpoint, this was the most compelling reason to attempt the day in 100-foot dives. Could my legs last?

What about DCS?

And finally, the sheer number of repeat dives to this depth would raise the specter of decompression illness. Typically, when freediving, nitrogen loading isn’t a significant concern. We’re not huffing breath after breath of pressurized air at depth, or typically accumulating hours of bottom time. But risks of freediving DCS (or ‘taravana’) go up quickly as dives get deeper, surface intervals get shorter, and when the dive count increases. There are no ‘freediving tables’ in use. However, we do have recommendations for safe surface intervals that have been extrapolated from scuba diving and seem to work very well, though actual research on freedivers is very limited, particularly when we start contemplating a high number of dives in the 30M range. It’s worth mentioning that Kirk Krack and PFI have pioneered the use of surface nitrox blends which could reduce the chance of freediving DCS. While this ‘technical freediving’ approach is a fantastic tool for motion picture stunts and photography, it’s blatantly against the rules in freedive or spearfishing competition. So, I wanted to stick to regular air, breathed normally.


Due to the realities of the time in the water, daylight, and temperature, I’d need to keep up a good pace. Based on a couple of training/feasibility sessions, I felt like I could physically maintain a pace of one drop to 100’ every four minutes in sets of 25, followed by a break to eat, warm-up, etc. Not counting breaks this would come out to 10 solid hours of in-water time and just over 2.5 hours of underwater time over the course of a day. From the freediving DCS standpoint, we’d be far outside accepted guidelines and deep into unknown territory. After consultation with some other PFI professionals, I decided that during the breaks I’d add a deco hang and breathe pure O2 for a few minutes at 5M, similar to what is done by some scuba divers who have exceeded the ‘no-decompression limit’. Many freediving competitions have also endorsed this approach as a best practice after particularly deep (60M+/200’+) single dives.

Figuring out where/when

After the initial idea, nothing actually happened with it for several weeks. I was busy with teaching, life, and the start of California spiny lobster season. I did a few feasibility tests on some training days to try and work out a realistic pace, and as always was keeping up my general strength and conditioning work. However, I made no firm plans until early November, when I suddenly realized that we’d be into winter soon and water temps—already starting to fall from an unseasonably warm late summer—would make a freedive Everest impossible. I flirted with the idea of trying to go to Kona and do it there, but well, I decided that might be too easy. Anybody could do this in 80F/27C water, no waves, and 100’ viz, right? But to keep it local would be a bigger challenge and mean something more to me.

Calling in the troops and final prep

It came together quickly. Based on my busy teaching schedule, it would need to happen in just over a week or it would never happen. Thursday, November 12 was to be the day. I put out a call to my training buddies—all solid, top local freedivers that I’ve known for years, several of them former students of mine—asking them to safety me throughout the day. Several enthusiastically agreed. Robert Lee, a northern California diver and PFI veteran instructor and Deja Blue safety, volunteered to drive down and coordinate the safety team. Bill Kiely offered the use of his Zodiac as a support boat. Pacific Wilderness, on short notice, started building my O2 deco rig. And photographer Wray Sinclair offered to come out and shoot some photos on the day. The site would, of course, be Veteran’s Park Beach, which is rather nondescript as far as dive locations go, but happens to be the terminus point of the Redondo Submarine Canyon and in my opinion the best nearshore deep training site in California. This is the site where I learned to freedive for real, where I did my first 40M, 50M, 60M, 65M dives.

With less than a week to go, I checked the water temp at Veteran’s. It was cooling, but still feasible. 69F/20C at the surface and 63F/17C at 100’/30m. The forecast for Thursday looked good. I was getting excited; I’d missed international competitions and felt jealous of my European brothers and sisters who started to get out of quarantine even hold small competitions.

This would be my chance to do something in 2020…

Then, over the weekend, four days out, everything changed. We had a cold snap. Winter came with a bang. Water temps dropped 10 degrees F/5C in the span of two days and air temps dropped 20F/14C. What was expected to be a really cool, fun challenge was suddenly looking more and more like a bitter slog through cramping muscles, hypoxia, and hypothermia, together with the ever-present specter of crippling neurological accidents.

Ironically, the first Freedive Everest was now looking like a true first ascent.

The day started at 3:30 am when Carlo and Lita, my first two safeties, met me at the harbor to wrangle boats. My trusty inflatable, a heavily modified Saturn Kaboat, was to be our dive platform, and we motored out to our spot off the beach. We set the dive line and safety counterweight in the dark. The water felt icy cold. The first dive started at 5:21 am, just as it was getting light.

The first set

I managed a set of 20, shivered through my first deco hang, then hauled myself onto the support Zodiac. I didn’t say anything to the effect, but I was DONE. There was no way I had another 130 drops in me. I didn’t want to call everything off since we’d loaded up the boats, and various dive buddies had committed to show up throughout the day and safety, some of them even taking off work to be there. I figured we’d just hang out on the water all day, do some winter training and for once, enjoy a nice boat loaded with snacks and hot coffee.

I realized then that Alasdair, the next safety on the schedule, had swum out and was bobbing next to the line, enjoying the clear morning sun and an uncharacteristically mellow ocean. In his rich, British accent, he said something to the effect of,

“My God, what a lovely day for diving.”

He was right. It really was a beautiful morning. I felt silly, sitting on the boat just off the beach, huddled in a dive parka.

Round 2

I got back in the water. My core had miraculously warmed a bit and more dives might even be…fun? I started to dive into the next set… And so on and so on it went throughout the day. I would finish each set tired and bitterly cold, but fresh divers just kept swimming out, bringing new energy and enthusiasm. Once we got through 70 dives, I realized I might conceivably finish. We were a little behind schedule, but everyone was positive and so was I.

Getting late…

When night fell, we still had 35 drops left to go (the number of total dives at this point was revised to 148 when Max, one of my final safeties, realized that I didn’t actually need to finish 150 to make Everest). The wind was picking up, temperatures were falling, and the sea was getting rougher. The deco O2 bottle was empty. The food was cold. Everything was wet. I took an informal poll,

“I think I can finish this thing, are you guys doing okay?” They looked at me like I was crazy for even hinting that we might quit and responded with a resounding, “hell yes, let’s do this!”

We pushed on in the dark with flashlights. Those last dives were the hardest; it became a high-wire act between muscles wanting to cramp, DCS concerns, the cold, and hypoxia, clattering off the plate in the dark and trying not to surface under my little inflatable boat that served as our dive platform. Purposefully, throughout the day I’d asked everyone not to announce dives remaining unless I asked, so as we neared the end, I knew we were very close to the excitement, but it wasn’t until I surfaced and everyone started yelling that I knew we made it. I smiled. Both legs seized instantly with cramps.


It took us 14 hours, 28 minutes, and 14 seconds to complete. One hundred forty-eight repetitions of a 100’/30.5M dive, done clean, constant weight, bi-fin.

Huge thanks to those who safetied on the day: Carlo Parducho, Lita Martinez, Alasdair Boyd, Armenak Toumanian, Michelle Villanueva, Jacob Macias, Justin Wood, Max Mossler, and Robert Lee for coordinating.


I thought long and hard about what equipment I would use for this attempt. Much of it is my ‘everyday’ gear for Southern California diving/training/spearing/teaching. I do receive discounts from some different vendors and manufacturers, but I’m not sponsored by any of these companies. This is gear I chose because I felt like it would be the best thing for the day. The fins and wetsuit would fall into the high-end category while most of the other stuff is relatively normal.

  • Eliossub 5mm smoothskin open cell wetsuit: 2 piece with integrated hood, high waist, custom fit, Heiwa medium density neoprene. I have been wearing this model suit for years and it’s my favorite for deep California diving/hunting. Certainly not for everyone, they last half as long as many other suits, can be harder to repair, have to be shipped from Italy, and are too delicate for serious lobster diving and rocky entries/exits. On the upside they are incredibly stretchy, comfortable to wear for many hours, low drag, warm, and windproof. I think I’m on my 4th one.
  • Meandros X-Pro medium stiffness fins with Pathos pockets (heat molded to my foot).
  • Aqualung Technisub MicroMask
  • Garmin Descent Mk1 watch. The myriad of smartwatch features are a bit much for me, but it’s a very rugged, reliable build with excellent battery life for a smartwatch, and is of course highly customizable for diving.
  • Cressi 2.5mm dive socks
  • Deepsea 5mm gloves. These are my serious ‘cold water’ gloves that I have previously only worn when hunting in water below 50F. They’re bulky, but have a double wrist seal which is not common.
  • Omer rubber belt, Marseille style buckle. This is a simple belt, but I prefer Marseille buckles for cold water diving as they’re easier to use with cold fingers or bulky gloves. The thickness of the belt is also good–slim enough to fit my weights but sturdy enough to carry a lot of lead without tearing.
  • Streamlined lead weights with set screws. I don’t know which company makes these, but they show up occasionally in some spearing stores and DIY molds are available. They are very comfy and streamlined, but pricey for lead weights since the mold is more complex, being a 3-part mold.
  • Generic stiletto type dive knife
  • Custom low-profile flashlight. I build these for lobster diving mostly and they aren’t available to the public. They are nearly indestructible, have 16 hour run time on low power, and feature a relatively warm, wide beam, similar to an UW video light. I mostly use them on low power; high power is too much for hunting but would be good for night video.


Below is a dive summary with a few further notes as well as the graphs from my Garmin Mk 1 Descent watch…

Freedive Everest: First Ascent

Achieved by Lance Lee Davis, 148 x 30.5M CWTB, in 14:24:18, on November 12, 2020, at Veteran’s Park Beach in Redondo Beach, California.

Set number

Start time

Total Everest drops

UW time

Surface time

Average depth (meters)

Max depth (meters)

Avg water temp

Min water temp

Max water temp

Deco time









































































1) These times are based on what my Garmin MK1 Descent watch software determined. Between sets 5 and 6 I forgot to take the watch out of dive mode, so set 6 metrics are actually totals of both sets 5 and 6. Underwater time and average depth on sets 1 – 4 also include my deco hang at the end. For more detailed, granular data consult the time/depth graphs.

2) Set no. 1 was actually 21 drops but is listed here as 20. The reason is that the first drop to 30M was done free immersion as a warm-up, and so I did not count it towards the total for the Everesting which I wanted to be clean CWTB.

3) Regarding deco: I had a tank of 100% O2 that I used for a 3M – 5M deco hang at the conclusion of sets 1 to 4. Tank ran out after that and I switched to some breaths out of a surface DAN type O2 emergency bottle after set 5 and 7. The time I breathed out of that bottle is listed on the chart but is an estimate. At no point during or after the day did I recognize any physical or neurological symptoms of DCS. These deco protocols were all precautionary.

4) During breaks, priority was first the deco hang followed immediately by trying to warm up and eat. I consumed mostly liquid food: Smoothies made from frozen fruit, peanut butter, and a generous amount of Muscle Milk (a vitamin fortified whey protein meal replacement that I love for exactly these kind of LONG days on the water). I also had a big thermos of hot coffee that had generous amounts of cream, butter, and Muscle Milk in it. For cold water diving I like to consume protein for thermic effect as well as a fair bit of fat for slowly digested, high-density calories. Besides the warming effect of food, the other thing that kept my core temp up was a big cooler of hot water—I’d take my gloves and booties off, throw on a dive parka and later even a subzero sleeping bag, then sit with my hands and feet in the cooler of hot water. Over the course of the day, I went through a little more than a gallon of liquid food/coffee. That night, after the day of diving, I weighed myself and had actually only dropped a pound from the morning.


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