Validation at sea for ulyx, the latest deep diving AUV for oceanographic research

The new 6000m depth capable AUV uly^x is scheduled to enter regular operational service within the French Oceanographic Fleet in 2024. Over the course of the past two years the AUV has featured a comprehensive technical validation program at sea. This article provides a description of the main features of the new system, focusing on the technological and innovative aspects introduced by the development project. An account of the main achievements of the first 76 dives of the AUV provides the outline of the path to full operational deployment.

I. Introduction

The French National Oceanographic Institute IFREMER has a proven track record of developing and operating underwater vehicles for the scientific exploration of the world oceans. Having pioneered the application of AUV technology for scientific data acquisition with the development and launch of the Epaulard AUV in 1982, the Institute has since developed and operated a comprehensive fleet of underwater platforms, both manned and robotic: the Nautile HOV, Victor 6000 ROV [1], Ariane HROV [2] and a pair of twin 3000m capable AUVs Aster^x and Idef^x [3]. Jointly funded by IFREMER, two of the French Ministries and the European Commission, the development of an innovative deep diving AUV begun in 2016 and under the codename CORAL project. This has produced the Institute’s new 6000m capable AUV uly^x and its comprehensive suite of scientific payload sensors and equipment. uly^x was designed and built through a tight cooperation between IFREMER and Exail (formerly ECA Group) and was first deployed for preliminary sea trials in December 2020. The AUV uly^x has since performed 76 dives at sea, featuring an average depth of 1100m and a maximum depth just shy of 4600m.