Glider

A glider, in ocean observation, is a buoyancy-driven autonomous underwater vehicle that profiles the water column on long endurance missions without a thruster. It pumps oil or water to change buoyancy and uses fixed wings to convert vertical motion into a sawtooth glide at about 0.25 m/s, surfacing periodically for GPS and Iridium telemetry. Slocum, Seaglider, and Spray gliders carry CTD, dissolved oxygen, chlorophyll fluorescence, and acoustic payloads, running for weeks to months and covering thousands of kilometers per deployment. Gliders bridge the spatial gap between fixed moorings and one-time ship surveys, holding station along repeated transects through storms.