Supplementary Material: Low-Cost Wearable Dive Computer for Monitoring, Logging and Presentation of Large-scale Freediving Studies

Due to the enormous spread and acceptance of wearables, it has become easier in recent years to collect physical data and use it to improve the living conditions of the wearer. On the other hand, there is the underwater world, in which technological development could not progress so quickly; mainly because the sealing of the device and the interaction with it, pose different and novel problems compared to more widespread wearables. To close this gap, a low-cost dive computer with a customizable set of sensors which is suitable for large-scale data collection for divers is presented in this contribution. This prototype makes use of existing electronic components such as sensors or modules aimed to develop a fully functional and low-cost portable system. In addition, the portable system is also able to store the data of all users bundled on a server for further research. These results cover two primary goals: (1) to provide an easily reproducible portable system at low cost, and (2) to collect data in an easily adaptable platform and its subsequent easy accessibility. Finally, the prototype was built based on the instructions and tested under real conditions.