applied sciences Article Designing a Diving Protocol for Thermocline Identification Using Dive Computers in Marine Citizen Science Salih Murat Egi 1,2 , Pierre-Yves Cousteau 3, Massimo Pieri 1, Carlo Cerrano 4,* , Tamer Özyigit 2,* and Alessandro Marroni 1 1 Research Department, DAN Europe Foundation, 64026 Roseto degli Abruzzi, Italy; [email protected] (S.M.E.); [email protected] (M.P.); [email protected] (A.M.) 2 Department of Computer Engineering, MTF, Galatasaray University, Istanbul 34349, Turkey 3 Cousteau Divers, 75017 Paris, France; [email protected] 4 Department of Life and Environmental Sciences—DiSVA, Università Politecnica delle Marche, 60131 Ancona, Italy * Correspondence: [email protected] (C.C.); [email protected] (T.Ö.); Tel.: +90-542-687-1410 (T.Ö.) Received: 17 September 2018; Accepted: 29 October 2018; Published: 20 November 2018 Abstract: Dive computers have an important potential for citizen science projects where recreational SCUBA divers can upload the depth temperature profile and the geolocation of the dive to a central database which may provide useful information about the subsurface temperature of the oceans. However, their accuracy may not be adequate and needs to be evaluated. The aim of this study is to assess the accuracy and precision of dive computers and provide guidelines in order to enable their contribution to citizen science projects. Twenty-two dive computers were evaluated during real ocean dives for consistency and scatter in the first phase. In the second phase, the dive computers were immersed in sufficient depth to initiate the dive record inside a precisely controlled sea aquarium while using a calibrated device as a reference. Results indicate that the dive computers do not have the accuracy required for monitoring temperature changes in the oceans, however, they can be used to detect thermoclines if the users follow a specific protocol with specific dive computers. This study enabled the authors to define this protocol based on the results of immersion in two different sea aquarium tanks set to two different temperatures in order to simulate the conditions of a thermocline. Keywords: diver; underwater; SCUBA; temperature measurement 1. Introduction Temperature data from the oceans are very important to understand the ecosystems and assess the human impact on nature. There is large scale monitoring of sea surface temperature using both remote sensing and in-situ platforms [1–4], but there is a lack of depth resolved temperature profiles for inshore regions, besides the use of ‘animals of opportunity’ [5,6] and human volunteers [7,8] which help to monitor the depths/temperature profile data to address this issue. In fact, Citizen Science (CS) is becoming a powerful tool, bringing together scientists, society and decision makers. Recent reviews show that the last decades have seen a tremendous increase in CS projects and participation, thanks to technological advances amongst other elements. CS projects have also made contributions to science [9–12]. Recreational SCUBA divers are one of the important contributors to marine citizen science. Their key instrument is a dive computer (DC) that they need to use in order to monitor depth, time and in some models the amount of gas remaining in their tank. Dive computers include algorithms to predict the likelihood of decompression sickness and calculate the safe ascent rate for a diver. For that reason, the modern electronic DC can be considered as the most significant advancement in diving Appl. Sci. 2018, 8, 2315; doi:10.3390/app8112315 www.mdpi.com/journal/applsci Appl. Sci. 2018, 8, x FOR PEER REVIEW 2 of 11 Appl. Sci. 2018, 8, 2315 2 of 11 safe ascent rate for a diver. For that reason, the modern electronic DC can be considered as the most significant advancement in diving since the invention of the Aqualung by J.Y. Cousteau. Modern sincedive computers the invention include of the an Aqualung interface to by allow J.Y. 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The aim of thisthis studystudy isis toto simulatesimulate thethe thermoclinethermocline with a pairpair ofof seasea aquariumaquarium basinsbasins andand determine thethe protocolprotocol toto bebe usedused toto detectdetect thethe thermoclinesthermoclines usingusing thethe divedive computercomputer logs.logs. 2. Methods 2.1. Open Water Dive 2.1. Open Water Dive Prior to controlled controlled experiments experiments in in a asea sea aquarium, aquarium, a SCUBA a SCUBA dive dive is planned is planned to verify to verify if the if dive the divecomputers computers are functioning are functioning properly. properly. The The Bosporus Bosporus Channel Channel dive dive site site was was selected, selected, where where thethe thermoclinethermocline due to to the the counter counter flow flow of of Mediterranean Mediterranean and and Black Black Sea Sea water water is iscommonly commonly observed observed at atvarying varying depths depths and and locations. locations. Gregg Gregg et al. et found al. found the theexchange exchange flow flow between between the Sea the Seaof Marmara of Marmara and andthe Black the Black Sea Seato be to bequasi-steady. quasi-steady. The The dive dive site site was was selected selected as as a apotential potential point point to to observe the temperaturetemperature gradients [[16].16]. A A team of 3 divers made a dive to 49 m for a totaltotal divedive timetime ofof 1616 minmin whilewhile carryingcarrying 2121 divedive computerscomputers attachedattached toto acrylicacrylic rodsrods (Figure(Figure1 ).1). Figure 1. OpenOpen water tests with real dives (March (21 March 21, 2018).2018). Appl. Sci. 2018,, 8,, 2315x FOR PEER REVIEW 3 of 11 At the end of the dive, depth, time and temperature profile data was uploaded to a desktop computerAt the