Almost a quarter of the Earth's ocean floor has now been mapped, according to a BBC article reporting on the second UN Ocean Conference, currently taking place Lisbon. In the last year alone, data covering an area roughly the size of Europe has been added - some from recent mapping activities, and some from sharing of existing archives.

The announcement was made by Seabed 2030, a collaborative project between The Nippon Foundation and the General Bathymetric Chart of the Oceans (GEBCO), which aims to complete the mapping of the world's oceans by 2030.

In order to achieve this, autonomous or semi-autonomous technologies will inevitably be required. Some of the more recent mapping data came from the 22-metre robotic boat Saildrone Surveyor on a 28 day journey between San Francisco and Honolulu last year. Saildrone was recently awarded the 2022 Ocean Awards' Innovation Award for revolutionizing ocean mapping - the Surveyor vessel representing "a paradigm shift in how we explore our oceans, carrying the same cutting-edge sonar equipment as survey ships to deliver high-resolution data to the global community, but operating at a fraction of the cost and carbon footprint".

Larger autonomous mapping vessels are also on the way - Southampton-based marine robotics company Ocean Infinity is currently building a fleet of 78 metre-long ships, which could eventually carry out extended mapping missions at a much lower cost than crewed vessels. And according to their website, Ocean Infinity's hybrid technology robotic vessels can produce as little as 1/10th of the emissions of a conventional ship and its crew.

Sea maps are important for many reasons, and in many fields of research, not least in climate-change models. While a complete map of the global sea bed would have seemed like science-fiction when I studied Oceanography (admittedly a few decades ago), recent developments in autonomous vessel technology have made it a distinct reality.

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