@jackrae - That actually is great information to have for the taut-wire system. Do you think it would be possible to, instead, reverse the idea of the taut-wire system? For example, have the depth sensor down with the diver as well as a waterproof trigger and then pull the tether taut and somehow register the angle at which the tether goes into the water from the buoy. Relatively new to this area with the Arduino so I'm not sure if there is a type of "ball-joint" sensor that can register this type of information but it seems do-able. Thank you again for your input on this and let me know if you have any knowledge on that type of sensor! I'll continue to search online for one and post back here if I find one.