Spray Glider

Except for the external bladder and measurement sensors, located in a plastic tail section, all parts are encased inside a thin, 8-millimeter (1/4-inch) aluminum hull. Several components allow the glider to move vertically and horizontally in the water as it dives repeatedly from the surface.

In the forward section of the glider, three batteries provide the instrument power and help it to control its orientation. The electronics bay houses computer components, the CTD instrument, a GPS receiver, and a satellite transmitter used for communications with researchers.

Spray Gliders have no external moving parts or motors. Instead, they move on a pre-programmed course vertically and horizontally in the water by pumping mineral oil between two bladders, one internal and the other external to the hull. This action changes the volume of the glider, making it denser or lighter than the surrounding water.

Note: in the diagram, the section aft of the wings is rotated by 90° to show the vertical tail. (Illustration by Jayne Doucette, WHOI)