September 2020

Life in Internal Waves; A Review of Secchi's Contributions; Advancing Ocean Observation with an AI-Driven Mobile Robotic Explorer; The Story of Plastic Pollution; and More…

Oceanography | September 2020



VOL.33, NO.3, SEPTEMBER 2020

Life in Internal Waves

A Review of

Secchi’s Contribution

to Marine Optics

Advancing Ocean

Observation with

an AI-Driven Mobile

Robotic Explorer

The Story of

Plastic Pollution:

From the Distant

Gyres to the Global

Policy State

Oceanography | Vol.33, No.3

Oceanography | September 2020


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VOL. 33, NO. 3, SEPTEMBER 2020



A Review of Secchi’s Contribution to Marine Optics and the Foundation

of Secchi Disk Science

By J. Pitarch


Life in Internal Waves

By J.C. Garwood, R.C. Musgrave, and A.J. Lucas



Advancing Ocean Observation with an AI-Driven Mobile Robotic Explorer

By A. Saad, A. Stahl, A. Våge, E. Davies, T. Nordam, N. Aberle, M. Ludvigsen, G. Johnsen,

J. Sousa, and K. Rajan



The Story of Plastic Pollution: From the Distant Ocean Gyres to the

Global Policy Stage

By C.M. Rochman



QUARTERDECK. Reflections

By E.S. Kappel


FROM THE PRESIDENT. Ocean Sciences During the Fall Season:

The End and the Beginning

By M. Visbeck


RIPPLE MARKS. Turn Off the Lights: Artificial Light at Night, a New Threat to

Beleaguered Coral Reefs

By C.L. Dybas


COMMENTARY. Equity and Safety in Polar Oceanography? Let’s Start with

Equal Chances of Survival. Literally.

By A. Glüder


COMMENTARY. Maury for Modern Times: Navigating a Racist Legacy in

Ocean Science

By P.K. Hardy and H.M. Rozwadowski


COMMENTARY. Integrating Oceanographic Research into High School

Curricula: Achieving Broader Impacts Through Systems Education

Experiences Modules

By M.V. Orellana, C. Ludwig, A.W. Thompson, and N.S. Baliga


COMMENTARY. Lessons Learned from Running a Conference in the Time of

COVID-19 and the Silver Linings of Shifting to Online

By H.E. Power, M.S.S. Broadfoot, A. Burke, P.M. Donaldson, R.M. Hart, K.C. Mollison,

D.J. Schmidt, and S.M. Young


HANDS-ON OCEANOGRAPHY. Sound and the Seafloor: Determining

Bathymetry Using Student-Built Acoustic Sensors

By R. Levine, S. Seroy, and D. Grünbaum


THE OCEANOGRAPHY CLASSROOM. A Viral Shift in Higher Education?

By S. Boxall


Oceanography | September 2020


Onshore-moving nonlinear internal waves in

the waters off La Jolla, California, concentrate

bands of the motile, bioluminescent dinoflagel-

late Lingulodinium polyedra. For more on how

horizontal drift and vertical swimming in inter-

nal waves modulate plankton's immediate envi-

ronment, see Garwood et al., in this issue. Photo

credit: Eddie Kisfaludy/SciFly

Oceanography | Vol.33, No.3


Ellen S. Kappel

Geosciences Professional

Services Inc.


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Johanna Adams


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ocean science and its applications. The journal presents significant research,

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University of Cambridge

Oceanography | Vol.33, No.3

Oceanography | September 2020



This September 2020 Oceanography doesn’t have a special issue

section, but if I had to provide a title for the issue, it would be

“Reflections.” Subjects the articles and commentaries ask us to

reflect on include racism and gender bias in the ocean sciences,

the benefits and pitfalls of conducting conferences virtually, les-

sons learned while developing broader impact activities, and the

optical oceanography legacy of Angelo Secchi, among others.

Some of the topics addressed here may take us out of our

comfort zones. Hardy and Rozwadowski reexamine the legacy

of nineteenth-century naval officer and early ocean scientist

Matthew Fontaine Maury. While Maury did not own slaves, his

actions supported the institution of slavery. Our authors pose the

question, what should ocean scientists “do with this new found

awakening to Maury’s dual admirable and reprehensible lega-

cies?” Applying contemporary standards to centuries-old conduct

is a challenging exercise, but we need to take the time to reflect on

how we teach about such historical figures as we simultaneously

develop strategies to increase diversity in the geosciences.

Glüder’s commentary addresses gender bias by examining an

extremely tangible example: why don’t many research vessels have

an adequate supply of survival equipment in smaller sizes suit-

able for women—and also for men who do not fit the “50th per-

centile North American male” physique. The issue here concerns

not only survival in frigid ocean waters but also the feeling of not

belonging caused by the lack of proper safety equipment.

The inclusion of “broader impact” activities is a requirement

for many science proposals submitted to US federal agencies.

Orellana et al. describe how they developed successful high

school ocean science curriculum modules and leveraged several

grants to retain continuity of the project. They also reflect on the

solutions that enabled the success of their broader impacts proj-

ect and share those lessons learned.

Thrust into this COVID world of relative isolation, conferences

have had to test the waters of the virtual world. Power et al. share

their experiences conducting a Young Coastal Scientists and

Engineers Conference online. They reflect on the numerous pos-

itive outcomes of holding a virtual conference, some unexpected,

and note that even when in-person conferences are again possi-

ble, they will likely always incorporate some online component.

The hands-on oceanography activity, “Sound and the Seafloor,”

by Levine et al. introduces students to the concept of acous-

tic reflection (sorry) by having them build their own simplified

echosounders, deploy their instruments to map a transect, and

use the data to explore sampling resolution. The article does have

a section called Reflection (really) in which the authors suggest

questions that can stimulate students to consider the implications

of their observations and the sources of variability.

Pitarch illuminates the optical oceanographic legacy of

Angelo Secchi, the nineteenth century Italian astrophysicist

widely known for the reflective (sorry again) white disk that

bears his name. In this article, Pitarch calls attention to a mostly

ignored 1865 cruise report in which Secchi addresses such ques-

tions as “how the angle of the sun, the disk’s color and direc-

tional reflectance, the disk’s diameter, the ship’s shadow, and

cloudiness influence the transparency measurements.”

In her Revelle Lecture article, Rochman tells the story the his-

tory of research surrounding plastic pollution in the ocean. She

reflects on how a little more than a dozen years ago, the words

plastic and pollution were not yet linked as an environmental

issue, but today plastic pollution has become a global policy

issue with research going in many new directions.

Other articles in this issue describe new and exciting ocean

science and engineering areas and take look at an important

topic of study that has been largely neglected. In their Breaking

Waves article, Saad et al. demonstrate how it is possible to inte-

grate artificial intelligence methods into an autonomous under-

water vehicle to accelerate the analysis of the spatiotemporal dis-

tribution of microorganisms in the ocean. In their Regular Issue

Feature, Garwood et al. use idealized numerical simulations to

show the importance of accounting for horizontal motions in

internal waves when studying coastal ecosystems.

If I may provide a couple of other important reflections from

this September issue: I am particularly pleased and proud to see

the number of graduate students and early career scientists who

are first authors (Garwood, Glüder, Levine, Saad) or coauthors

(in Levine et al., Power et al., Saad et al.) of articles. I am also

very encouraged that women are first authors (Garwood, Glüder,

Hardy, Orellana, Power, Rochman, Saad) on seven of the nine

articles—perhaps a counterbalance to some of the data coming

out that indicates women are publishing less during COVID.

One final reflection. While Oceanography has “grown up”

considerably since it was first published in 1988, this September

issue also displays how we have remained true to our roots.

As the first Oceanography editor David A. Brooks wrote in

the inaugural magazine issue, “the guiding principle and edi-

torial policy of Oceanography Magazine will remain steadfast

and inviolate: we intend to serve, promote, and chronicle all

aspects of ocean science and its applications, and we invite you

to join in the adventure.”

Ellen S. Kappel, Editor


Oceanography | Vol.33, No.3


Ocean Sciences During the Fall Season:

The End and the Beginning

For those who live in the higher latitudes of the Northern

Hemisphere, the fall season usually marks the end of summer

fieldwork. This year, for some of us, the field season never fully

started or didn’t happen at all, as the coronavirus pandemic

changed the world. Many oceanographers were unable to ven-

ture out to sea, take samples, and observe and record environ-

mental conditions. We could not proudly look back on a new

discovery or an exciting data set that should prove our hypothe-

sis or provide new insights into an ocean process. We could not

deploy a new set of autonomous instruments to collect contin-

uous observations and celebrate its success. In a pre-pandemic

world, we would now be looking forward to working up field

data in our offices and laboratories and repairing and refurbish-

ing instruments. Maybe we would also be catching our breath

and reflecting on the season.

The pandemic has noticeably impacted many other aspects

of our work. During late spring, access to laboratories was sig-

nificantly restricted, and our intricate plans for the summer

field season were falling apart. New plans needed to be made

quickly and were obsolete again a short time later. We needed

to be flexible and were constantly adjusting the way we perform

our science. We felt exhausted before the field season began,

not knowing if, in fact, it even would begin. Instantly, most of

our communications were switched to digital media. There was

no sharing of a coffee, no bumping into a colleague randomly,

no chitchats with students and staff. Hope for a quick return to

“normal” gave way to the realization that the global pandemic

will be with us for many months to come.

Today, we are still weary. The field season was barely produc-

tive. We participate in a seemingly endless stream of online meet-

ings. We are tired of staring at the computer screen and long for

those days in the field and when we could meet in person with

colleagues. Although we move less physically, the rapid switch-

ing from online meeting to online meeting leaves us breathless

and exhausted. We simply need a break from it all.

On the other hand, the fall season also marks a beginning. It

is typically when many expert gatherings happen where we share

our discoveries and discuss and debate our science with col-

leagues. It is also the time to publish and teach. Moreover, it is

a time to begin planning for the next field season and assemble

new teams, establish new partnerships, and sketch out a new proj-

ect or experimental setup. The anticipation of the next summer’s

field season with better sensors or more instruments, a new ship

or platform, or a more promising location keeps us optimistic.

Fall is also a good time to consider our plans for ocean sci-

ences in the coming years and post-pandemic times. As a result

of the pandemic, TOS learned how to run electronic meetings

efficiently. We’ve had more TOS Council meetings than in past

years, with much greater attendance. We miss the social inter-

actions, but our meetings are now shorter, with stringent agen-

das, and the frequent use of electronic voting tools helps to

rapidly come to consensus. There seems little desire to go back

to in-person Council meetings.

What have we accomplished at TOS? We have established

three new awards—TOS Mentoring, TOS Early Career, and

TOS Ocean Observing—and have grown our student member-

ship dramatically. We have also used this year to reflect gener-

ally on the ocean science community engaged in TOS. Have we

succeeded in connecting to and fully embracing new opportu-

nities? As a first step in reaching out further, the TOS Council

established three new Council positions: one to bring in the per-

spective of the early career scientist, one to engage deeper with

the ocean data and informatics community, and one to enhance

connections with the areas of social science, ocean policy, and

ocean governance. We also considered the broad profile of

our TOS membership and the ocean sciences community and

determined that TOS does not fully reflect the diversity of the

greater society. We established a JEDI committee that is charged

with making concrete suggestions to advance issues of justice,

equity, diversity, and inclusion. The committee will support the

TOS community in embracing and celebrating our differences,

broadening participation, and creating a culture of belonging.

Moreover, we are engaging in deep discussions about the future

of our Ocean Sciences Meetings, with the next one scheduled

for 2022 in Hawai‘i. What is the optimal mix of in-person and

remote participation? How will the business model shift? How

can we best support our TOS and ocean sciences communities?

Looking back over 2020, we mourn a partially missed field

season, personal hardships, and significant disruptions. At

The Oceanography Society, we have only partially completed

our TOS 2030 Strategy process. But once the winter season

wanes, we expect that all of us will feel energized and ready for

a new ocean science season. We look forward to deeply engag-

ing with our membership to develop an exciting, innovative,

impactful, and inclusive TOS Strategy 2030 in order to shape the

future of our Society.

Martin Visbeck, TOS President

Oceanography | September 2020

Satellite view of artificial light

at night. Credit: NASA



Satellite images of Earth at night: bright

dots and shining webs that tell the story of

humans’ seemingly endless sprawl across

the globe.

Artificial “sky glow” can now be detected

along 22% of the world’s shorelines. That

figure is expected to increase dramatically

as human populations along coasts more

than double by 2060.

All that light has a downside. Concerns

have recently bubbled up about the dam-

aging effect of artificial light at night, also

known as ALAN, on humans and other spe-

cies. At the top of the list are coral reefs.

Artificial light at night and how it affects

corals is the subject of new research by

scientists at several institutions, including

the University of Southampton in the UK.

With funding from the UK Natural Envi-

ronment Research Council, Southampton

scientists Jörg Wiedenmann and Cecilia

D’Angelo of the university’s  Coral Reef

Laboratory are tackling gaps in our under-

standing of how ALAN affects the repro-

duction of reef corals.

They are working with a team at Bangor

University and other UK research institu-

tions, the Interuniversity Institute for Marine

Sciences in Eilat, Israel, and the Horniman

Museum in London. The research is part of

a larger project led by University of Bangor

scientists studying the impacts of artificial

light at night on marine life.

“ALAN represents an emerging threat

that has received little attention in the

context of coral reefs, despite the poten-

tial of disrupting the chronobiology, phys-

iology, behavior, and other biological

processes of coral reef organisms,” write

Inbal Ayalon and Oren Levy of Bar-Ilan

University and their colleagues in a 2019

paper in Global Change Biology.

Coral reefs are in decline as a result

of climate change, coastal construction,

overfishing, pollution, and nutrient enrich-

ment, says Wiedenmann. “The key to

coral reef survival is for the remaining indi-

viduals to produce enough offspring that

can survive on damaged reefs and help

the reefs recover.”

ALAN, however, presents a major road-


To maximize reproductive success, many

corals release their eggs and sperm at the

same time, sometimes on only a single

night of the year in a process called mass

coral spawning. The timing of spawning is

thought to be synchronized with and trig-

gered by the light of the moon. Scientists

fear that increasing levels of artificial light

at night may override age-old signals from

moonlight, resulting in less efficient coral

reproduction and reduced recruitment of

juvenile corals.

Coastlines are exposed to artificial light

at night near piers, promenades, ports,

harbors, and dockyards. They’re increas-

ingly illuminated with LED lighting, which

penetrates deeper into seawater than

older lighting technologies. LED lighting is

predicted to make up 69% of global light-

ing by the end of this year, exacerbating

ALAN’s effects.

The presence of artificial light in coastal

regions has the potential to interfere with

natural light cycles, ultimately reshap-

ing the ecology of coastal habitats, says

Wiedenmann. “We know that many

marine invertebrates are extremely sen-

sitive to natural light throughout their life

cycles, and that gradients of light intensity

and color, largely caused by variations in

moonlight and sunlight, are major factors

in marine ecosystems.”

Artificial Light at Night, a New

Threat to Beleaguered Coral Reefs

By Cheryl Lyn Dybas

Oceanography | September 2020


Oceanography | Vol.33, No.3

Coral spawning is a spectacularly synchronized event. The larg-

est coral mass spawning event in the world takes place on the

Great Barrier Reef off the coast of Australia. Credit: Oren Levy

He and colleagues believe scientists

need to find out how much damage is

caused by artificial light at night and quan-

tify the benefits of less intense forms of

artificial light on corals and other sensitive

marine species. That information, accord-

ing to Wiedenmann, is vital to the future

of coastal habitats, especially coral reefs,

around the world.




In a discovery that scientists believe will

help guide reef ecosystem protection

plans, researchers in Australia and Israel

have pinpointed artificial light at night as

a threat to coral reproduction on the Great

Barrier Reef.

Work at the University of Queensland’s

Heron Island Research Station confirms

that the Great Barrier Reef’s annual coral

spawning is dependent on an intricate mix

of conditions, with moonlight playing a

vital role. The introduction of artificial light

at night competes with moonlight and can

prevent corals from spawning, the univer-

sity’s Paulina Kaniewska, Oren Levy of Bar-

Ilan University, and their colleagues found.

The research is providing insights into

how corals have fine-tuned and coordi-

nated the release of eggs and sperm into

the water for fertilization. The results are

published in the journal eLifeSciences.

Corals have a “spread-out” nervous sys-

tem that allows them to transmit signals on

a cellular level in response to changes in

light conditions, according to Kaniewska

and coauthors. Their study suggests that

these cellular processes are triggered by

a protein similar to photosensitive melan-

opsin, one of a family of light-sensitive ret-

ina proteins, called opsins, in vertebrate

eyes. In mammals, melanopsin plays an

important role in synchronizing circadian

rhythms with the daily light-dark cycle.

The research is resolving long- standing

questions about how corals synchronize

the mass release of their reproductive

cells with the phases of the moon and

other rhythms. The effects of light on the

timing of spawning are important because

reproduction is vital to reef survival, the

scientists say. They believe that light pollu-

tion is a major threat to coral reproduction.

Coral spawning on the Great Barrier

Reef is a spectacularly synchronized

event. Changes in water temperature,

tides, sunrise and sunset, and the intensity

of moonlight trigger an annual large-scale

mass spawning of coral species.

To maximize their chances of success,

more than 130 Great Barrier Reef coral

species spawn during a time window that

is 30–60 minutes long. It’s the largest

coral mass spawning event in the world.

Most corals are “broadcast spawners”

that simultaneously release their eggs and

sperm into seawater. The egg and sperm

cells combine and develop into larvae that

settle back onto the reef to form new coral

colonies. Coral species spawn at the same

time to improve their chances of success-

ful reproduction.

How corals time this spawning behav-

ior with moon phases was an unanswered

question for decades. Then, Kaniewska





millepora— one of the dominant coral

species on the Great Barrier Reef—to

different light treatments and sampled

the corals before, during, and after their

spawning periods.

The results show that light causes

changes to gene expression and sig-

naling processes inside the corals’ cells.

The changes drive the release of egg and

sperm cells and happen only on the nights

of spawning.

Next, the researchers exposed Acropora

millepora to light conditions that mimic

artificial light at night. A mismatch in cel-

lular signaling processes prevented the

corals from spawning.

The findings also suggest that the

effects of light pollution can occur fairly

rapidly. Biologists believed that corals took

months to become tuned to the moon-

light rhythms that guide reproduction. But,

it turns out, disruption can occur within

seven days of corals’ exposure to changes

in nocturnal light.

In another study, Levy’s team recently

looked at two coral species, Acropora

eurystoma and Pocillopora damicornis,

in the Gulf of Eilat/Aqaba in the Red Sea.

“The region is undergoing urban develop-

ment that has led to severe light pollution

at night,” Levy says.

The research revealed that corals

exposed to ALAN photosynthesize less.

“Testing different lights such as blue LEDs

and white LEDs showed more extreme

impacts in comparison to yellow LEDs,”

Oceanography | September 2020

state the biologists in Global Change

Biology. The work lends yet more cre-

dence to the emerging threat of light pol-

lution and its impacts on the biology of

corals, says Levy, “and will help in find-

ing ways of mitigating potentially harmful

effects. Reducing the exposure of corals

to artificial light at night could help protect

and regenerate coral reefs.”




The light-hearted movie Finding Nemo

could soon have a much darker sequel.

Artificial light at night in coral reefs leaves

the famous reef clownfish unable to pro-

duce offspring.

Studies by scientists at Australia’s

Flinders University and the University






Letters  show that an increasing amount

of artificial light at night in coral reefs,

even at relatively low levels, masks nat-

ural cues that trigger clownfish eggs to

hatch after dusk.

Lead author Emily Fobert of the

University of Melbourne says that eggs

incubated in the presence of artificial light

had a zero hatching success rate.

“The overwhelming finding is that arti-

ficial light pollution can have a devastat-

ing effect on the reproductive success of

coral reef fish,” says Fobert. “When ALAN

was present, no eggs hatched but when

the light was removed during the recov-

ery period, eggs from the ALAN exposure

hatched normally. The presence of light is

clearly interfering with an environmental

cue that initiates hatching in clownfish.”

Fobert monitored 10 breeding pairs of

clownfish exposed to an overhead LED

that imitated commercially available and

widely used lights.

The results indicate that increasing

amounts of light at night can significantly

reduce reproduction in reef fish. “These

findings likely extend to other reef fish as

many share similar reproductive behav-

iors, including the timing of hatching

during early evening,” says Fobert.

Some tropical tourist hotspots include

floating accommodations above coral

reefs. Many overwater bungalows have

glass floors with lights shining directly

onto reefs below so guests can watch

fish at night.

Coauthor Stephen Swearer of the Uni-

versity of Melbourne says that clownfish,

along with many other fish species that lay

eggs on coral reefs, are at particular risk

because their larvae usually hatch a few

hours after dusk. “The presence of ALAN

could compromise their natural spawning

rhythms,” he says.

Karen Burke da Silva of Flinders

University, also a coauthor, believes

that an improved understanding of the

impacts of ALAN on coral reefs can lead

to solutions for these stressed ecosys-

tems. “Artificial light at night is becoming

a greater concern among ecologists. Light

is increasing globally and the impacts on

organisms can be severe, but very little

research has been done on ALAN in the

marine environment.”

If we don’t find ways of decreasing artifi-

cial light at night, “Nemo” and his kin may

be among the last clownfish on the reef.

Whither go the clownfish, the rest of the

coral ecosystem may soon follow.

It’s high time, researchers say, to turn off

the lights.


Cheryl Lyn Dybas (, a

Fellow of the International League of Conservation

Writers, is a contributing writer for Oceanography

and a marine ecologist. She also writes about sci-

ence and the environment for National Geographic,

BioScience, National Wildlife, Ocean Geographic,

Canadian Geographic, and many other publications.

Researchers are studying the effect of artificial light at

night on reef clownfish reproduction. Credit: University

of Melbourne/Flinders University

Oceanography | September 2020

Oceanography | Vol.33, No.3


Equity and Safety in Polar Oceanography?

Let’s Start with Equal Chances of Survival. Literally.

By Anna Glüder

As seagoing Earth scientists, we are used

to taking safety procedures, safety train-

ing, and safety equipment very seriously.

Understandably so: working on ships in

remote regions means that accidents have

the potential to be life-threatening. As a

result, the precautions taken to minimize

the risks of hazards are intended to be

detailed and comprehensive.

Here, I highlight an opportunity for

leadership to extend this strong advocacy

for safety during field operations to an

area that has historically been neglected:

consideration of body sizes other than the

“standard male” when equipping research

ships with survival equipment.

Immersion suits, flight suits, life jack-

ets, and foul weather gear are commonly

stocked as one-size-fits-all. For me, a

160 cm (5 ft, 3 in) tall woman, practice

putting on an immersion suit aboard a

ship usually triggers well- intentioned

jokes about how it could fit several peo-

ple my size rather than questioning

whether in case of a true emergency I

would be adequately protected. In the

words of a mate of a major research ship

who recently provided training on how

to don the immersion suits: “We have

the standard suits, and then some larger

ones and a few extra-large ones. If you are

small, sorry, they are probably not going

to work that well.”

They are not going to work that well. In

Arctic waters, your survival chance with-

out any protection is less than 15 min-

utes. Immersion suits are rated to prolong

that time span to up to six hours, given

a water-tight seal around wrists and neck

and an ideal trim (good fit) after most of

the air is purged from the suit.

The University-National Oceanographic

Laboratory System (UNOLS) safety stan-

dards state that “immersion suits are

required for vessels operating north of

32 degrees north and south of 32 degrees

south and should be type approved under

series 46 CFR 160.171” (UNOLS, 2015,

p. 17-2). The US Code of Federal Regu-

lations (CFR), 46 CFR 160.171-17 speci-

fies that in order to be approved, general

testing has to be conducted on three

females and seven males of three physical

body types. Required tests include don-

ning time, field of vision, walking, climb-

ing, righting, and water and air penetra-

tion. Testing related to thermal protection

is listed separately and specifically calls for

male test subjects to be used. Why has this

testing not been updated to account for

women’s body types?

The International Convention for the

Safety of Life at Sea (SOLAS) adopts reg-

ulations following resolution Msc.81(7),

which are slightly different and require

at least one of six test persons to be a

woman (IMO, 1998). However, in order

to test thermal protections, manikins can

be used that represent the 50th percentile

North American male.

For both UNOLS and SOLAS, the

required thermal protection states that

the wearer’s body temperature may not

drop by more than two degrees when

immersed for six hours in water between

0° and 2°C. The studies on which these

and other legal requirements are based

were conducted on—yes—male vol-

unteers or manikins representing the

50th percentile North American male

(Tipton, 1995; Lewandowski and Clark,

2016). These immersion suit tests con-

trast with the initial studies determining

the rate of heat loss in Arctic waters with-

out any protection, which featured both

males and females (Hayward et al., 1975;

Hayward, 1984).

Not only are the requirements for sur-

vival suits vague, current studies appear

to have skipped even considering what

equipment would be safe for anyone other

than the 50th percentile male. Perhaps this

oversight led to blog posts such as this

one, written from D/V JOIDES Resolution

where immersion suits are supplied in

four different sizes, including a small

one: “There are four basic sizes—small,

medium, large and extra-large. Those

of us on the smaller end of small, how-

ever, are doomed to surviving without

seeing— the zipper comes up level with

our foreheads” (https://joidesresolution.


A suit that is too large will fail in mul-

tiple ways. The most critical function

of immersion protective clothing is to

keep the clothing worn beneath them

dry. Tipton (1995) shows that the criti-

cal limit of cold-water intrusion before

a significant reduction of survival time

is 200 ml (i.e., not quite a cup). It’s easy

to see that an ill-fitting seal at neck and

wrists can be deadly.

A second path to failure is the addition

of buoyancy in the attached boot space.

Most immersion suits are outfitted with

an internal life jacket designed to keep

the head above water to prevent drown-

ing. To work properly, as much air as pos-

sible must be expelled from inside the suit

when donning. The more space there is,

the more difficult it is to push out all the

extra air, which in a worst-case scenario,

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