The Cave Pearls have grown into a robust Arduino based underwater logging platform, that is easy to assemble from preexisting components, which can be adapted to many other environmental monitoring applications. The datalogger itself is open-source, with parts, code, build instructions, etc. available at: https://thecavepearlproject.org/how-to-build-an-arduino-data-logger/ We've developed a "minimum build" of the research logger for classroom instruction, using Dupont jumper cables to reduce the assembly time to about 1 hour. The starter code provided on Github includes support for using the multi-color indicator LED as a light sensor, so the logger can be integrated into educational curriculum even if adopters don't add any extra sensors. https://thecavepearlproject.org/2023/12/01/the-e360-a-classroom-data-logger-for-science/ We have been using this simple data logger in an environmental monitoring course to help students learn how to program the Arduino to support sensors & communication. When connected to a USB cable, this logger can also act as a simple data acquisition system, displaying sensor data from real time experiments using the new graphing function built into the free Arduino software.