Project Hermes

In a nutshell

The ocean is losing biodiversity at an alarming rate due to pollution, overfishing, and climate change. The ocean’s temperatures greatly influence the planet’s climate, weather, fish stocks, bird populations… yet a detailed understanding of how these temperatures vary at depth, at the scale of coastal ecosystems remains poorly known to science.

Citizen science and crowdsourcing can plug this hole in our knowledge of coastal ocean temperatures. It is a vital source of information that governments, scientists, fisheries, and conservation organizations need in order to better understand, protect, and manage the ocean.

We are monitoring the temperatures of the coastal ocean at depth worldwide in near real-time, combining satellite surface temperatures and diver measurements, using sensors ranging from precision instruments to dive computer profiles.

Seems straightforward, right? Surprisingly, it is not.

Project Hermes at a glance by Michel Naufal

How hard can it be?

It turns out that measuring something as seemingly trivial as temperature is far more complex than I had originally hoped. In 2015, Cousteau Divers launched the project with a crowdfunding campaign on IndieGoGo. Every scuba diver and freediver has been recording the temperature of the ocean during his or her dives using dive computers for as long as they have existed. Originally, the plan was to collect these dive computer profiles to reveal this data worldwide in near real-time. As we found, though, current dive computers’ temperature measurements are completely inadequate for scientific purposes — some more than others, but all of them are off by a long shot.

The crowdfunding campaign and pre-campaign raised close to $10,000 USD, thanks to the generous support of over 200 contributors. Unfortunately, this fell short of the campaign’s goal, and since then I have not managed to raise additional funds for the development of the project. Notwithstanding, and with the help of several dedicated key partners and volunteers, we have found solutions to keep moving forwards, and we will deploy the first prototypes this year.

Infographic by Alissa Metsnik

Why does this matter?

The ocean absorbs 90% of the planet’s total heat. It produces more than half the oxygen we happen to breathe. It feeds hundreds of millions of people. It runs the climate show on our planet, pumping cold fresh water from the polar regions and circulating saltier warmer waters from the equator in a process called the thermohaline circulation, or “conveyor belt”. The ocean is the air conditioning system of planet Earth.

How can we sustainably manage marine resources when we don’t even know the temperatures of the ocean? This fundamental parameter is key to understanding how the ocean absorbs and releases energy. It influences fish and bird populations, weather patterns, and storm formation. Knowing the ocean’s temperatures at shallow depths has further potential applications for tourism and coastal monitoring.

There is an existing global system of oceanographic buoys deployed in the high seas called Argo. It provides bulk geographic information about many ocean parameters, including temperature, in the high seas. It does not, however, provide any insights on how temperatures vary at shallow depths along the coasts, where the vast majority of marine life dwells.

Thermoclines are thresholds between two layers of different temperatures in the ocean. Sometimes they can be quite abrupt, and the temperature can drop by several degrees with only a few centimeters of depth change. This layering of the ocean’s temperatures is something we know little about today… something we plan to help better understand.

The team

Things take a long time when funding is tight, but thanks to the interest and goodwill of key partners and volunteers, we look forward to deploying this first phase in June 2018.

During the past 18 months, our project partner Divers Alert Network (DAN) Europe was able to further investigate the feasibility of the project. Their research team, led by Dr. Murat Egi and Massimo Pierri, has been testing a wide range of commercially available dive computers in different temperature conditions. DAN Europe, through its online platform Dive Safety Guardian, has been collecting thousands of dive profiles for behavioral and physiological research.

By mining this information and carrying out specific tests, they have attempted to model the errors of the computers in the hopes they would be predictable and possible to compensate for. Their research has recently concluded that current dive computers are too inaccurate, with unpredictable error margins as well as high thermal inertia and low sampling rates, making them impractical for research on temperatures and thermoclines.

This month, we carried out a test campaign in the Bosphorus channel, near Istanbul in Turkey. In this channel, the surface waters flow from the Black Sea while the bottom waters are Mediterranean, creating a permanent thermocline. Surprisingly the surface temperature can be significantly lower than at depth (~7C vs ~13C). We dove into the channel with over 20 different dive computers in order to compare their performance.

As we descended into the green cold waters along our safety line, we passed hundreds of jellyfish. We reached the end of the safety line around 30 meters depth. But still no thermocline. Determined to make the test useful, we decided to continue our descent, as the current was very gentle. Plunging into increasing darkness, we suddenly felt the warm waters of the Mediterranean and at 48 meters we hit the bottom of the channel. After staying for as long as our no-decompression limit allowed, in order to give the computers time to settle at the ambient temperature, we made our way back up to our safety stop (which was impossible to miss, with over a dozen dive computers beeping to signal it!).

Pics by Ali Ethem Keskin

The next day, the team from DAN Europe was performing controlled conditions testing in the Istanbul Aquarium, successively plunging the same computers into tanks of different temperatures in order to model their settling rates. DAN Europe is currently compiling this data which will soon be published.

For this project we have abandoned the original idea of relying solely on available dive computers to measure temperature. But we didn’t give up the goal of monitoring and revealing the coastal temperatures of the ocean, a key missing piece of data in the puzzle of understanding how the ocean stores and releases energy, affecting biodiversity and climate. Today DAN Europe is developing a precision temperature sensor prototype in view of creating a new generation of dive computers.

The University of Queensland has been most helpful in the initial stages of the project. In particular, the excellent advice of Professor Ove Hoegh-Guldberg, who field-tested one of the candidate sensors for the pilot deployment and helped confirm the scientific potential of the project, has been invaluable.

The European Meteorological Satellite operating company (EUMETSAT) joined a few months ago, interested in both the citizen science aspect and the actual data from the project. They have invited me to give a TEDx talk and have been providing insights on the requirements for the diver measurements to be as pertinent as possible for use with satellite sea surface temperatures.

Last but not least, in the past several weeks the technical challenge and our open source values have attracted a new group of young engineers to the project: Brad Bazemore and Brendan Walters. With backgrounds ranging from robotics at the University of Georgia to computational neuroscience at Harvard, they have leveraged their tech industry experience to design an innovative approach that we hope will leapfrog our development efforts in several dimensions. They have already built and begun to test their first prototype precision temperature sensor as well as a cloud-based application that will automate both the process of data collection and presentation to the broader public.

Project Hermes prototype and testing by Brad and Brendan

Combining the data from precision sensors and dive computers, we believe that in time, we will achieve the project’s original goal: to reveal the temperatures of the ocean with scientifically valuable accuracy, globally, in near real-time, at citizen-science-level cost, integrating the data from dive computers and other sources.

Together we are now preparing to deploy both precision prototypes in a selected group of dive centers, with the hope of demonstrating the process and raising funds for a wider roll-out.

Open source values

At the heart of this project and everything Cousteau Divers does is the notion of the empowerment of people. We want to help you do good deeds for the ocean. We develop these tools because we believe in the power of numbers to help better understand and protect the ocean.

If you are a diver and are interested in contributing your data, please join us. If you would like to buy or build and deploy your own sensor, please join us. If you are an ocean lover who wants to support this kind of work, please join us. This project is one of many citizen science initiatives enabling every one of us to make a difference. Sign up at and follow our social media channels for more information.

Phase one launch and events

We will be launching the first prototype sensors during the second week of June 2018 in Santorini, Greece, where Cousteau Divers has been working for the past six years to create a marine protected area. During that week we will also be removing ghost nets from the seabed with our partner Healthy Seas. Join us online for live streams and follow us on social media for more news and updates!

Thanks to our donors

My sincere thanks to all the donors, volunteers and organisations (listed below) who have supported the project thus far. The money raised during the crowdfunding is financing the development and initial deployment of a dozen sensors in pilot locations. I look forward to sending more updates as the project unfolds. To better protect the ocean, we must better understand it. It may seem like a drop in the ocean, but that’s what the waves of change are made of.


Brad Bazemore, Olivia Pinon Fischer, Alissa Metsnik, Michel Naufal, Stephanie Stefanski, Apostolos Stylianopoulos, Brendon Walters, Georg Zoeller.

Supporting organisations

DAN Europe, University of Queensland Global Change Institute, EUMETSAT, NOAA Coral Reef Watch, Vellmari Formentera, Atlantis Diving Santorini, Plymouth Marine Laboratory, National Geographic, IUCN, UNEP, Mares, Plateforme Ocean-Climat, Waterproof Expeditions.

Crowdfunding donors

Adrian Fernandez, Alban Olivry, Alex Dulude, Alexander Reichardt And Katharina Bolesch, Alexia Dunand, Amiot, Ana Vilatella Domenjo, Andy Fischtrom, Anthias, Aquatours Almeria Aventuras Submarinas, Arthur Vaccarino, Atlantis Dive Center Santorini, Bahar Egi, Bertrand Laussinotte, Buceo Ciesub, Carla, Catherine, Catherine Kim, Chris Gibson,  Chris Welch, Christopher Drew, Clarisse Moreno, Cristina Garcia, Cynthia Ochoa, Daj Rose, Descamps, Della Ross, Denis Regnier, Diane Cousteau, Diego Acevedo, Donald Coleman, Estelle Donse, Franck Machu, Gatis Erins, Georg Zoeller, Giffaut, Glo, Gonzalo Barrio Perez, Guillaume Racine, Hakan Kjellqvist, Hector Salvador, Helen Klimmek, Helene Delcommune, Hernandez Sanchez, Hilo Ocean Adventures, Ivan Conesa Alcolea, Jacqueline Lee, Janis Krops, Jean-Pascal Quod, Jean-Paul Morales, Jenna LoDico cummings, Jens Altmann-Hughes, Jeremy Kemp, Joao de Sousa, Jodie Rowe, John Reid, John Rossant, José Luis Pérez Campos, Juan Mora Cresp, Juliana Dutra, Julien Blanchet, Jungwoon Ryu, Karen Nazor, Karim Fathalla El Mufti, Kathleen Russell, Kathryn O’Hara, Kerri Schlottman, Kim Angel, Konstantinos Demiropoulos, Louise, Louise Imbsen, Lorenzo Fornari, Luis Campos Rodrigues, Maelle Denoual, Maite Trujillo, Manisha Ahluwalia, Marc Pointel, Max Friess, Marcelo Colombo, Martin Kielland, Mary Waters, Matthew Killick, Michael Garin, Michelle Lemech, Milko Vuille, Murielle Merlin, Nasser Bakkar, Olivia Meylan, Olivier Saut, Pascal Boichut, Patrick St-Onge, Paul Sharp, Peter Harlock, Philip Ling, Philippe Valdois, Poyan Abrahimi, Raegan Payne, Raynaud, Recker, Rene Laufer, Richard Evey, Robert Guinness, Roberta Grubbs, Ronald Goldstein, Sandra Kropa, Sandra Palomera, Sea Star Water Sports Aqaba, Shirley Lail, Simon Banks, Stephanie Stefanski, Suzanne Smith, Sylvia Earle, Tarik Chekchak, Tero Juola, Thorsten Thiele, Tuukka Haarni, Vishwanath Rajan, Wiggo Eriksen, Xong Sing Yap.

(does not include donors who chose to remain anonymous, listed alphabetically by first name as provided to Indiegogo and during the pre-campaign)

Online articles


17 thoughts on “Project Hermes

  1. Stationed off St. Augustine, Florida. I do not know if the European organizations are intrested in western temperatures but I’m interested in participating in the program. Let me know your thoughts.

    Liked by 1 person

  2. Hello,

    I operate an environmentaly friendly diving service in Florida and I would really like to contribute to your work if I could. I operate off a boat 5 days a week and complete nearly 20 dives a week all at different locations. If we could be of service to your organization in anyway please contact me.

    Liked by 1 person

      1. Bonjour Pierre Yves
        Nous nous étions croisé lors de ta venue à Nouméa et avions parlé de la ponte du corail. Je suis sur que la technologie de Sigfox (startup toulousaine) peux aider dans ton projet. Je suis partenaire pour la NC et couvre largement plus de 50% du lagon et beaucoup des cotes sont couvertes dans plus de 51 pays. N’hesites Pas si tu veux des infos


  3. Hi,

    We have developed underwater navigation system named UWIS. There we have real time position data as well temperatures available in surface and in diver side. Also those are stored into log files. It would be interesting to hear what kind of targets you have for temperature accuracy and would our system support Hermes project somehow. Please visit in

    Liked by 1 person

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