FIELD NOTES: THE COLD STUDY

There is a moment, about forty minutes into a cold water session when a long lull suddenly leads your next decision. You're getting cold. Your legs feel heavier. Your paddle is a half-beat slower. Waiting for the next set feels further away than it did an hour ago. Most surfers learn to read that moment intuitively. You either push through it or you're catching one more in.

What almost no surfer has ever been able to ask is a simple question: "How is my wetsuit actually performing, right now, at minute forty?"

For as long as wetsuits have existed, the industry's answer has been some version of "trust us." Thicker is warmer. Limestone is better than petroleum. This fleece is a game-changer. The marketing language has always run well ahead of the measurement. That gap between what the industry traditionally claims about wetsuits and what can actually be proven about them in the ocean is where the Standard Issue Fullsuit was designed.

Our Research Lab

We exist to make equipment for a life spent in the ocean. That framing matters, because equipment is something you test. Equipment has tolerances and failure points and honest performance curves. Equipment isn't styled. It's engineered, used, broken, and refined.

"With our wetsuit program, what we're trying to do is base our decisions off of data and science versus marketing and sales," says Bruce Moore, our Director of Innovation and Sustainability.

It's a sentence that sounds almost defensive until you understand what preceded it. Bruce has been in the wetsuit industry long enough to watch a lot of categories get born during a marketing meeting instead of the lineup. Bigger claims. Bolder graphics. Thinner proof.

So when we began designing our next generation of fullsuits, we made a different kind of commitment: we would partner with researchers who had no reason to care about our marketing calendar and we would let their data tell us what to build.

Research & Development

The partner we found was about an hour down the coast from our Newport Beach headquarters, inside the Kinesiology department at California State University San Marcos.

Surfing has historically been a terrible research subject. It's variable. It's wet. It's unpredictable. Participants don't stay still. The environment refuses to replicate. As a result, despite surfing being practiced by an estimated 37 million people worldwide — with well over two million in the United States alone — the sport has generated remarkably little peer-reviewed science. As Dr. Sean Newcomer and his co-authors noted in their 2018 paper in Ergonomics, the first to characterize regional skin temperatures in recreational surfers wearing a wetsuit: "despite the increase in popularity, there is a paucity of research on the physiological aspects of recreational surfing."

Almost nobody had bothered to study what wetsuits actually do.

CSUSM changed that. A group of professors there had spent years standing up one of the only academic programs in the country focused on the biomechanics, physiology, and health benefits of surfing. They had the instruments. They had the methodology. They had the patience to chase data into cold water at 6 a.m. What they did not have was an equipment company willing to let the findings drive the design.

"We built this relationship quite a few years ago," Bruce says, "and we've been learning more and more about how the body functions in a surfing environment. And now, more specifically, how wetsuits function in a surfing environment."

That is where the Standard Issue Fullsuit began.

The principal investigator on the skin-temperature work, Dr. Sean Newcomer — Professor in the Department of Kinesiology at CSUSM, and a co-author on the 2018 Ergonomics paper that first put surfing thermoregulation into the peer-reviewed literature — frames the scope of the project plainly:

"Over the past six months we have had the opportunity to work with FLORENCE on a research project investigating the insulation capacity of a variety of wetsuit materials in a field setting. These studies were performed by a group of graduate and undergraduate students from California State University San Marcos at local Southern California beaches on over 80 surfers ranging in age from 18 to 50 years old. The results of these studies allowed FLORENCE to optimize material location and type to increase warmth during surfing with their new innovative wetsuit design."
Dr. Sean C. Newcomer, PhD, Professor, Department of Kinesiology, California State University San Marcos

Eighty surfers. Six months. Actual ocean. That is the dataset behind the suit.

Every wetsuit on the market is a set of assumptions about heat. Assumptions about which parts of your body lose it fastest. Assumptions about which materials hold it best. Assumptions about what a surfer will trade — flexibility, weight, cost — to keep it.

We wanted to replace the assumptions with measurements. Specifically, we wanted answers to two questions that would shape the entire architecture of the new suit:

1. Does bio-based foam actually keep a surfer as warm as traditional chloroprene neoprene? If the answer was yes, there was no longer a performance argument for building suits out of petroleum.
2. Where on the body does a high-loft fleece lining actually make a thermal difference? If we could map that, we could stop lining entire suits on faith and start placing fleece only where it mattered.

Both questions had been asked before in catalogs. Neither had been answered in water.

The protocol, refined across multiple sessions with CSUSM graduate researchers, is meticulous. Each participant is instrumented with an array of iButton wireless thermal sensors — small, waterproof thermistors, applied at precise anatomical landmarks that had been validated in earlier CSUSM work.

As one of the graduate researchers walked us through on a recent morning at 54th Street in Newport Beach, "the sensors are placed ten centimeters lateral to the umbilicus, two centimeters inferior to the clavicle, on the upper arm between the acromion process and the glenohumeral head, and on the thigh along the vastus lateralis between the femur and the patella." Those sites aren't arbitrary. They represent regions of the body that thermoregulate differently, and losing data from any one of them would blur the picture.

Once instrumented, participants surf. Not simulate surfing. Not paddle in a pool. Surf. For at least an hour, in the Pacific, participating in the acts of paddling, sitting, and wave-riding that makes up a real session. The sensors log skin temperature every sixty seconds. Water temperature and air temperature are captured at the site. At the end of the session, the data is downloaded and the surfer is debriefed on what felt warmer, more comfortable, and more flexible. Because perception matters too.

To isolate the variable of interest, material not suit, each suit was built as a split prototype: one side of the body in one material, the other side in another. The surfer becomes their own control. As our CSUSM collaborator put it, "In a lab-based study, it wouldn't be as applicable for surfers that surf every day in varying water temperatures and varying air temperatures. It's important that we take measures of those."

 

What the data said about foam

The first preliminary study we want to share compared our new plant-based bio foam against traditional chloroprene neoprene, held constant across a full hour of surfing in split-side prototype suits.

The headline finding is almost anticlimactic, and that is exactly what makes it important.

Averaged across every sensor site on the body, there was no meaningful thermal difference between the two foams (p = 0.654). Over sixty minutes of real surfing, skin temperatures under the bio foam tracked the chloroprene curve so closely that the two lines are nearly indistinguishable on the chart.

At individual sites, the picture is more interesting, and more honest. Chloroprene held a small but statistically significant edge at the chest. Bio foam actually ran significantly warmer at the upper arm and leg. The abdomen was a wash.

The perceptual data told the same story in the subjects' own words. When we asked which side of the suit felt warmer, the largest group said the same. Asked about comfort, the largest group said the same. Asked about flexibility, the same.

For us, that is a green light written in data. The common industry assumption that you have to trade warmth to get a cleaner material isn't holding up in the water. Bio foam performs at parity with chloroprene in the environment that actually matters. Where small regional differences appeared, we now know exactly where to compensate in construction.

The second test on the same material: mechanics, not just warmth

Thermal parity is half the equation. The other half is how a foam actually behaves under the repeated stretch and rebound of surfing: paddling out, duck-diving, wrestling the suit on and off.

To answer that, we sent samples of both foams to the lab of Dr. Jeff Nessler, Associate Dean of the College of Education, Health, and Human Services at CSUSM, who ran controlled tensile stretch tests on matched specimens. Dr. Nessler is also a co-author on the 2018 Ergonomics paper and one of the researchers who has helped build the foundational measurement protocols behind this entire program, so the mechanical work was held to the same standard as the thermal work.

The numbers came back clean, and they are worth stating precisely:

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- Tensile strength at failure: Bio foam [3.38 MPa] vs. traditional foam [3.05 MPa]
- Tensile strain at failure: Bio foam [512%] vs. traditional foam [473%]
- Stiffness across the stretch range (tangent modulus at 10–70% strain): both foams tracking closely, with small, consistent offsets rather than dramatic divergence.

Translating out of engineering units: both foams stretched to roughly five times their resting length before rupturing. For context, Dr. Nessler's lab has separately measured that a wetsuit only sees about 50% stretch, half a resting length, during normal in-water use. Even accounting for the much higher stretch of pulling a suit on and off, both of these foams are operating at a fraction of their actual failure envelope.

Two things fall out of that data.

First, the bio foam is not the fragile cousin of traditional neoprene. On the two numbers that matter most for durability (ultimate strength and ultimate elongation) it came in slightly ahead of the petroleum-based control.

Second, both of the foams we're building with today are a meaningful step forward from where the industry was even a few years ago. In Dr. Nessler's words, both current foams are "much more flexible and stronger than the samples that we ran a couple of years ago." The baseline has moved.

Stack the preliminary thermal study and the preliminary mechanical study side by side and the conclusion compounds: the bio-based foam is not a sustainability compromise dressed up in green marketing. It is thermally equivalent, mechanically equivalent or better, and grounded in the same in-field rigor as everything else in this program.

What the data said about fleece

The final preliminary study was sharper, and in some ways more useful for design.

Here we compared a high-loft grid fleece inner lining against a jersey interior, again split across the body, again over an hour of surfing. Across the whole body, fleece was significantly warmer than no-fleece. That's the finding the industry has always claimed, and yes, it holds up. But the more valuable finding was where fleece mattered and, crucially, where it didn't.

On the upper arm and chest, fleece produced a statistically significant thermal advantage that held across the hour. These are the regions most exposed to flushing and air-contact heat loss while a surfer is sitting upright between sets. On the abdomen and legs, fleece did not produce a statistically significant thermal benefit. The legs in particular, submerged most of the session, insulated by water that's been warmed against the skin simply didn't need it.

Then the perceptual data added a final, decisive piece of information. A majority of subjects reported the fleece side felt warmer, while an even larger majority reported the non-fleece side felt more flexible.

Read those two preliminary numbers together and a design principle falls out: Fleece is a tool, not a blanket. Used everywhere, it costs you real flexibility in exchange for thermal gains that, in some regions, don't exist. Used only in the regions where the data proves it pays, it gives you warmth where you need it and range of motion where you need that.

From data to production garment

These are the studies that shaped the Standard Issue Fullsuit.

Three changes, each of which can now be traced to a specific finding in the preliminary CSUSM dataset rather than a designer's hunch:

Grid fleece, reconfigured. Rather than lining the suit end-to-end, we placed the high-loft grid fleece in the regions where it produced a measurable thermal advantage, the torso and upper chest, and removed it from the regions where it only cost flexibility. The suit feels lighter in the lower legs because it is lighter in the lower legs, and the data says you won't miss it.

Bio foam, validated. Thermally and mechanically. With the parity finding from the field thermal study and the tensile data from Dr. Nessler's lab both in hand, we were able to commit to our plant-based foam construction without asking the surfer to accept a warmth penalty or a durability penalty. The more sustainable choice was also, measurably, the equivalent choice. And in ultimate strength and stretch, a marginally better one.

Neck and shoulder refinement to reduce flushing. The regional temperature maps across every session we ran told a consistent story about where cold water enters the suit during duck-dives and wipeouts. We responded with a refined neck and shoulder panel geometry, and a streamlined drawcord and fastener closure at the chest for a cleaner, more secure seal.

Every one of those decisions is one we can now prove with preliminary data.

The point of all of this.

We believe the people who spend their lives in cold water deserve data backed equipment. They deserve equipment whose claims can be checked. They deserve material decisions that are defensible in a peer-reviewed methodology, not just a catalog. They deserve the same thing climbers and cyclists and runners have long taken for granted: a relationship between what the product says and what the product does.

"For me personally, I'm very passionate about this because we're basing decisions off of fact," Bruce says. "These studies have actually never been done before. It's all been trial and error to get wetsuits to this point. And now what we're doing is taking those decisions to the next level by actually being able to study these materials."

This is the first FLORENCE wetsuit built entirely inside that framework. It will not be the last. The partnership with CSUSM is ongoing, the sensors are already back in the water.

Thicker isn't always warmer. Fleece isn't always better. Bio isn't always a compromise.

We had the questions the whole time. We just finally learned who to ask.

The Standard Issue Fullsuit is available to FLORENCE Members for pre-order ahead of an early October delivery. 

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Field thermal research led by Dr. Sean C. Newcomer, Professor in the Department of Kinesiology at California State University San Marcos, with tensile mechanical testing conducted by Dr. Jeff Nessler, Associate Dean of the College of Education, Health, and Human Services at CSUSM. Program builds on the foundational work of Corona, Simmons, Nessler, and Newcomer published in Ergonomics (2018).