The Southern Ocean surrounding Antarctica is a region that is key to a range of climatic and oceanographic processes with worldwide effects, and is characterised by high biological productivity and biodiversity. Since 2013, the International Bathymetric Chart of the Southern Ocean (IBCSO) has represented the most comprehensive compilation of bathymetry for the Southern Ocean south of 60°S. Recently, the IBCSO Project has combined its efforts with the Nippon Foundation – GEBCO Seabed 2030 Project supporting the goal of mapping the world’s oceans by 2030. New datasets initiated a second version of IBCSO (IBCSO v2). This version extends to 50°S (covering approximately 2.4 times the area of seafloor of the previous version) including the gateways of the Antarctic Circumpolar Current and the Antarctic circumpolar frontal systems. Due to increased (multibeam) data coverage, IBCSO v2 significantly improves the overall representation of the Southern Ocean seafloor and resolves many submarine landforms in more detail. This makes IBCSO v2 the most authoritative seafloor map of the area south of 50°S.

The methods of data collection, processing, and assessment of the quality of the results of a survey conducted at the Southern Ionian Sea off the Messinian Peninsula, Greece are presented. Data were collected by the GEBCO-Nippon Foundation Alumni Team, competing in the Shell Ocean Discovery XPRIZE, during the Final Round of the competition. Data acquisition was conducted by the means of unmanned vehicles only. The mapping system was composed of a single deep water AUV (Autonomous Underwater Vehicle), equipped with a high-resolution synthetic aperture sonar HISAS 1032 and multibeam echosounder EM 2040, partnered with a USV (Unmanned Surface Vessel). The USV provided positioning data as well as mapping the seafloor from the surface, using a hull-mounted multibeam echosounder EM 304. Bathymetry and imagery data were collected for 24 h and then processed for 48 h, with the extensive use of cloud technology and automatic data processing. Finally, all datasets were combined to generate a 5-m resolution bathymetric surface, as an example of the deep-water mapping capabilities of the unmanned vehicles’ cooperation and their sensors’ integration.

The concept for an autonomous seafloor mapping system for ocean exploration is being built to compete in the Shell Ocean Discovery XPRIZE competition (http://oceandiscovery. xprize.org) by the international team of Nippon Foundation / GEBCO Alumni (see: http://www.gebco-nf.com/). The Team is advised and mentored by selected GEBCO and industry experts, specialized in ocean mapping, geology, software development and naval architecture. The Team is distinguished by its extraordinary diversity with a global distribution of representatives from academic institutions, offshore survey and technology industries, as well as national hydrographic offices. A newly designed, innovative Unmanned Surface Vessel (USV), called SEA-KIT, will be built to cooperate with any Autonomous Underwater Vehicle (AUV) acting as the remote surface access to the deep ocean. The major role of the SEA-KIT in the competition design is 1) the transportation of a commercially available AUV to and from the land launch site to the survey area and 2) the deployment and recovery of the AUV. Additionally, the SEA-KIT surface vessel will offer a positioning solution during AUV operations. Furthermore, if the USV is equipped with hydroacoustic devices, it can function as a stand-alone survey platform for any water depths dependent on the characteristics of the mounted echosounder. Positioning of the SEA-KIT will be realized using the High-Precision Global Navigation Satellite System (GNSS) positioning data. Satellite and radio communication solutions will be used for data transmission between the remote offshore system and the home base (onshore or mothership) components. Communication between SEA-KIT and the AUV will be performed by means of acoustic signals from an Ultra Short Base Line (USBL) device. Those signals are used for positioning and underwater data transmission. This data will be used for continuous AUV position calculation, using information about the AUV position relative to SEA-KIT. SEA-KIT will also be equipped with an Acoustic Doppler Velocity Log (DVL), Pressure Depth Sensor and an Inertial Measurement Unit (IMU). Automated functions for data processing will be considered.