The Expendable Bathythermograph (XBT) probe (see Figures) is a device for obtaining a record of temperature as a function of depth from a moving ocean vessel. As the probe descends through the water, the data is transmitted to the ship via two very thin wires which pay out from both a spool dropped with the probe and one retained on the ship. The data is recorded on a computer in real-time and transmitted to land via satellite. These probes can reach depths up to 1500 meters.

The Atlantic Oceanographic and Meteorological Laboratory (AOML) collects oceanographic data from voluntary vessels of the Ship of Opportunity Program (SOOP). NOAA supports five High Density (HD) XBT lines AX7, AX8, AX10, AX18, AX25. On these lines, it is necessary to deploy XBTs on a 24-hour schedule as the ship steams along its course. It would take at least two people to be able to conduct around the clock operations. In order to reduce the workload and personnel, AOML has designed an XBT probe autolauncher that will allow this work to be performed by one person. The autolauncher can be preloaded with up to eight probes and then deployed at predetermined launch times or positions. The operation of the autolauncher is controlled by SEAS 2K, a real-time software product developed at AOML.