True or false. Small unmanned, underwater gliders are able to make water property measurements for months before being retrieved?

True. Unmanned underwater gliders are suitable platform for cost-effective, long-term monitoring of shelf sea ecosystems.

Autonomous underwater gliders, represent a rapidly-maturing technology with a large cost-saving potential over currently available ocean sampling techniques, especially for sustained, month at a time, real-time oceanographic measurements.

Underwater gliders move efficiently through the water-column by exploiting their ability to change their weight in water. As a frequent communications and shallow dives, which imply frequent changes in buoyancy, is an increase in power consumption and therefore a reduction in mission length.

Currently the operational endurance of the gliders varies from 3 to 4 weeks for the shallow SLOCUM glider (max. depth ≤ 200m) to several months for the deeper diving gliders Seaglider (max. depth ≤ 1000m) and Spray (max. depth ≤ 1500m).

All three gliders are comparable in size and handling requirements. Their weight in air is approximately 50 kg and their total volume change capacity is between 0.5 and 1% of their total displacement. The horizontal speed relative to the surrounding water is typically around 35 cm/s.

Gliders may be equipped with a wide variety of sensors to monitor temperature, salinity, currents, and other ocean conditions. This information creates a more complete picture of what is happening in the ocean, as well as trends scientists might not otherwise be able to detect from satellites or large research ships.

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