Drifters Do it Yourself (D2iY), an integrated project to learn oceanography by building and deploying surface drifters.

Within the frame of the Master in Oceanography of the University of Liège (Belgium), a two-week research stay is held every year at research station STARESO (Station de Recherches Sous-Marines) in the Bay of Calvi in Corsica (France). During these two weeks, the students can put in practice the theoretical concepts they have acquired during their classes. This includes pelagic and benthic measuring campaigns to measure ocean currents, temperature and salinity, fluorescence, dissolved oxygen, etc. The students also dive to observe the Posidonia meadows, their extension and density, as well as the inhabitants of this rich ecosystem.

Since 2023, and with the support of the University of Liège, we have developed the program “Drifters Do it Yourself” (D²iY), in which the students build deriving platforms (surface drifters) equipped with different sensors, that they deploy during the 2-week field trip. The drifters measure the ocean currents and temperature of the water, and are built out of wood (the mast) and fabric (the sails) in order to keep the price low and prioritising sustainable materials. This project aims at developing a wide array of student competences, going from the conception and building of the platform, the programming of a Raspberry Pi that commands the measurements and communication with the shore, the design of the measuring strategy and the analysis of the results obtained. Working in groups of 3-4 students, cooperation and teamwork are necessary in order to successfully finish the project. The students are driven to think about the best strategies to sample the Bay of Calvi, including the depth and frequency of measurements. The robustness of the drifters is put to a tough test when deriving with the ocean currents, which also makes the students think about the special needs of measuring in harsh environments. Once the drifters are recovered, they analyse the results and compare them with other sources of information, which also allows them to assess the accuracy of their data. Being able to build a project from scratch makes the students much more aware of what it is needed to design a successful measuring campaign and allows them to integrate the knowledge they acquire in the different theoretical lessons and put it to work in a fun and cooperative way. The project keeps evolving year to year to include new sensors and platform designs, and also to integrate suggestions provided by the students after their experience with the drifters. The complete source code to log and send the position via the GSM network and post-processing the data to compute surface currents is available at https://github.com/gher-uliege/drifter-raspberry-pi.