A new observing system that provides deep repeated profiles of the oceanic kinetic energy dissipation rate and small-scale mixing is presented. The system is designed to provide 300 dissipation rate profiles using a vehicle that cycles along a mooring line from the sub-surface down to a maximum depth of 4000 m. The system was tested for two weeks between 630 and 1700 m during a cruise that took place on the Lucky Strike segment of the Mid-Atlantic Ridge. The vehicle collected 35 profiles at a mean downcast velocity of 0.63 m s−1. To quantify the quality of the measurements, profiles from the mooring are compared with nearby profiles from an autonomous microstructure free-falling instrument. The dissipation rate noise level varies between O(10−10) and O(10−9) W kg−1. This noise level is low enough to detect turbulent patches at depth. The largest dissipation rate measured at this site was O(10−7) W kg−1.