The document describes the MuFUwECoRe, a bio-logger being redesigned to record the underwater behavior of elephant seals and other marine mammals. It is expected to function continuously for 1 year at depths of up to 3000 psi and temperatures from 0-40°C. It will record data like location, depth, temperature, salinity, and speed to provide physiological information about seals. Sensors will measure these environmental conditions and wireless transmission will send the data.