This work addresses a long-standing problem in using large water samplers at sea where the terminal velocity of the sampler sinking through the water column is less than the wire to which it is attached. Without careful management and complex motion compensation devices, data can be degraded, and excessive snap loads can develop causing the cable to break. This project will involve mechanical design, prototype construction and testing of a water sampler attachment mechanism that will decouple the underwater instrument package from its wire during descent. The sampler will be allowed to free-fall at its natural, and constant terminal velocity, independent of the hydrographic wire's ship- induced movement. Once at full depth, a mechanical device will firmly couple the instrument package to the wire for retrieval back to the surface. A constant and predicable descent rate through the water column will improve the quality of oceanographic data and lessen the chance of losing instruments from cable management problems. This work has a direct bearing and use on several global geoscience research initiatives.
