Vast amounts of the world’s shipping sails unseen

In maritime legendUN, the traversed the world’s oceans undetectable except to the naked eye. Its mysterious voyages have inspired poems, novels, an opera, and, it would seem, an armada of imitators.According to a new study in , three-quarters of all industrial fishing vessels and a quarter of transport and energy ships (a category that includes oil tankers, cargo ships, passenger ships and support vessels), have been left out of previous tallies of human activity at sea. The oversight is substantial—the has previously calculated that the maritime economy represents a value of $1.5trn a year.