Deployments in extreme conditions: Pushing the boundaries of Seaglider capabilities

Over the last couple of decades, autonomous underwater vehicles have become a powerful tool in the investigation of biological, chemical and physical oceanography. Not only do they complement existing technologies, they open up new avenues of investigation through their specific capabilities. For AUVs to benefit from the same success other long term monitoring platforms have had (moorings, ARGO), it is critical to understand their limits in both monitoring and process studies. We present results from several Seaglider deployments by the University of East Anglia where Seagliders were pushed to the limit of their abilities. Comparison of missions in extreme conditions at the limits of their depth range (70 to 1000 m) and battery life shows a need for tailored survey design and flight parameters in order to maximise mission duration, control over the Seaglider and most efficient science sampling. In particular, we look at post-processing of Seaglider data and present aspects of a new MATLAB toolbox which greatly improves on timestamp correction of Seaglider data by accounting for errors introduced by using a single thread processor.