Superyachts are usually associated with luxury travel, but the 68-metre Archimedes, owned by Jim and Marilyn Simons at the time of the research, also became a platform for marine science. During several deployments between 2018 and 2020, an autonomous measurement system aboard the yacht collected ocean-colour observations at a range of locations, including remote regions such as the Antarctic Peninsula. The yacht’s crew set up the equipment and managed it as conditions changed, while scientists from Plymouth Marine Laboratory and the University of Exeter processed and analysed the resulting data. The measurements allowed researchers to assess satellite-derived ocean reflectance, a key step in using satellite observations to study phytoplankton and marine ecosystems. In a peer-reviewed perspective published in January 2024, titled Superyachts could support satellite ocean colour validation, the researchers described the project as a pilot demonstrating the potential of private vessels to supplement ocean monitoring.
Jim and Marilyn Simons and the Archimedes: how philanthropy supported ocean research
The collaboration grew out of scientific research and philanthropy. Jim and Marilyn Simons co-founded the Simons Foundation in 1994 to advance research in mathematics and the basic sciences. The foundation supports CBIOMES, a project launched in 2016 to develop and apply computational models of marine microbial communities. Dr Shubha Sathyendranath of Plymouth Marine Laboratory, a scientist associated with CBIOMES, met Jim Simons at a meeting in New York. She and Dr Robert Brewin of the University of Exeter, both specialists in satellite ocean colour, subsequently became involved in the initiative using the Archimedes. The Simons made the yacht available for scientific measurements, providing researchers with an additional platform for collecting observations during its voyages.The measurement system was designed to operate autonomously. The yacht’s crew set it up and removed or replaced it as conditions required, including when weather changed between rough and calmer conditions. The data were then transmitted to Brewin’s team at the University of Exeter for analysis. Plymouth Marine Laboratory counted five instruments in the system. The peer-reviewed paper describes a solar-tracker unit fitted with two radiance sensors and one irradiance sensor, together with a pyrometer that measured infrared radiation from the ocean’s surface. However, the sea-surface-temperature data from the pyrometer were not used in this validation study. The solar tracker helped maintain the appropriate viewing geometry relative to the sun. According to the laboratory, the setup weighed approximately 80 pounds and cost about $80,000. Jim Simons died on 10 May 2024, aged 86, as the Simons Foundation announced. The project illustrates how private vessels can offer additional opportunities for scientific observation when their equipment, crew and routes can support research.
How satellite ocean-colour validation works
Satellite instruments measure ocean colour across vast areas, but the light they detect includes substantial contributions from the atmosphere and sunlight reflected from the water’s surface. Plymouth Marine Laboratory explains that less than 10% of the detected light originates from the ocean itself. Scientists must account for these other contributions before interpreting satellite measurements as information about the water. The system aboard the Archimedes recorded total radiance from the water surface, which includes light reflected from the sky, as well as sky radiance. Researchers used these measurements to calculate remote-sensing reflectance after correcting for the contribution of sky reflection. This value can then be compared with satellite-derived reflectance to assess the accuracy of satellite observations. The 2024 paper compared the yacht’s measurements with observations from NASA’s MODIS-Aqua satellite sensor at six wavelengths. The researchers reported that the bias and error in their comparisons at the blue wavelengths of 412 and 443 nanometres were slightly higher than those reported in other validation studies. At wavelengths from 488 to 667 nanometres, the bias and error were lower than or comparable to those in the studies used for comparison.The authors suggested that the difference likely reflected the more recent period covered by their validation measurements, during which MODIS-Aqua’s blue bands had degraded. This qualification is important: the results supported the potential of yacht-based measurements, but also showed that comparisons depend on the condition of the satellite instrument and the period over which observations are collected. Satellite-derived ocean reflectance is used in research on phytoplankton and marine ecosystems. Phytoplankton are microscopic organisms that form the foundation of marine food webs. Through photosynthesis, they take up carbon dioxide and contribute to the movement of carbon through the ocean. Ocean-colour data can also help researchers monitor harmful algal blooms and study productive waters that support fisheries. Cloud cover presents another limitation for satellite ocean-colour observations because clouds can prevent instruments from observing the sea surface. Vessel-based measurements can provide complementary observations, but the Archimedes study filtered out cloudy data. Its findings therefore do not demonstrate that the system could validate satellite ocean colour under cloudy skies. Rather, the pilot showed that a suitably equipped private vessel could collect useful measurements under appropriate observation conditions.
Superyacht science challenges: open-source systems and data sharing
The approach also encountered practical difficulties. The solar tracker originally purchased for the Archimedes was later discontinued by its manufacturer. The researchers identified alternatives such as the open-source Solar-tracking Radiometry platform, or So-Rad, which is designed to support ocean-colour measurements from moving platforms. The measurement system also began to degrade towards the end of the 2018–2020 deployment period, according to the paper. Data transmission and communication between scientists and the yacht’s crew were important to the project. The team used File Transfer Protocol to transfer measurements, a method that worked but did not enable near-real-time processing. The experience highlighted the practical importance of equipment reliability and coordination between researchers and vessel operators.Making measurements available to other scientists was another priority. The Archimedes dataset is accessible through NASA’s SeaBASS archive and the Simons Foundation’s Collaborative Marine Atlas Project, known as CMap. Brewin also worked with Dirk Aurin, affiliated with NASA Goddard through the Universities Space Research Association, on open-source processing code, supporting wider use of the data. Hyperspectral observations could expand the scientific value of ocean-colour monitoring. Traditional multispectral sensors measure light in a limited number of wavelength bands, whereas hyperspectral instruments capture much finer spectral information. NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite, launched in February 2024, carries an Ocean Color Instrument designed to measure light across a broad range of wavelengths. These observations can help scientists investigate differences among phytoplankton groups through their optical signatures, supporting research into marine ecosystems and the carbon cycle.The authors present the Archimedes project as a pilot study and argue that superyacht owners could be engaged as citizen scientists to help address gaps in ocean monitoring. The findings do not establish that private yachts can replace dedicated research vessels or that the same results would be obtained on every vessel. Instead, they demonstrate the potential for an appropriately equipped yacht to contribute useful measurements for satellite ocean-colour validation. The study offers a basis for further exploration of how private vessels could complement established scientific monitoring efforts.