APL-UW Home Page

   Russ Light  
      Principal Engineer  
      Ocean Engineering Dept.  
      Applied Physics Laboratory  
      University of Washington  

   Craig Lee  
      Senior Oceanographer  
      Ocean Physics Dept.  
      Applied Physics Laboratory  
      University of Washington  

   Marc Stewart  
      Senior Physicist  
      Electronic and Information Systems Dept.  
      Applied Physics Laboratory  
      University of Washington  


   Office of Naval Research  
      Tom Curtin  
      Tom Swean  


Seagliders fly through the water with extremely modest energy requirements using changes in buoyancy for thrust coupled with a stable, low-drag, hydrodynamic shape. Designed to operate at depths up to 1000 meters, the hull compresses as it sinks, matching the compressibility of seawater.

The autonomous underwater vehicle (AUV)
Seaglider is the result of a collaborative effort between APL-UW and the UW School of Oceanography. These small, free-swimming vehicles can gather conductivity-temperature-depth (CTD) data from the ocean for months at a time and transmit it to shore in near-real time via satellite data telemetry.

Seagliders make oceanographic measurements traditionally collected by research vessels or moored instruments, but at a fraction of the cost. They can survey along a transect, profile at a fixed location, and can be commanded to alter their sampling strategies throughout a mission.

Seaglider's cylindrical hull is a series of arched anodized aluminum panels separated by ring frames. The hull is surrounded by a fiberglass fairing to give it a low drag shape.


After each dive Seaglider dips its nose to raise its antenna out of the water. It determines its position via GPS, calls in via Iridium data telemetry satellite, uploads the oceanographic data it just collected, then downloads a file complete with any new instructions.


Seaglider is 1.8 m long and weighs 52 kg—a size and weight that allow easy launching and recovery by two people from a small boat.


Seaglider can travel at slopes as gentle as 1:5 or as steep as 3:1. At gentle glide slopes the vehicle transits most efficiently, while steeper slopes are used to maintain position and act as a "virtual mooring."