Autonomous underwater vehicles for seafloor observatories: challenges and opportunities

Summary form only given. The capabilities of autonomous underwater vehicles have been steadily increasing in recent years, and they are beginning to make critical contributions to seagoing scientific programs. In many cases, AUVs now operate for extended periods completely independent of a surface vessel, freeing the vessel to perform other tasks. However, nearly all of this work is conducted in a conventional expeditionary style: AUVs are deployed, operate until their on-board energy is consumed, then return to the surface for recovery. Between dives their batteries are recharged, a new mission program is downloaded, and a number of maintenance checks are performed. Cable subsea observatories can act as bases for long-term deployment of AUVs, giving them unprecedented capabilities for both extended time series observations and the ability to respond to events. A cabled observatory can provide the high-speed data links required for specifying missions and uploading large data sets as well as the power to recharge batteries. In this paper, we present a series of technological steps to extend our present expeditionary capability to a more sustained presence, which could culminate in observatory-based AUVs. We outline a series of demonstrations; each expected to return new and interesting scientific data that extend our AUV capability incrementally, culminating in a fully autonomous, long-term deployable AUV system.