With the ocean moving more than 90% of world commerce, keeping it secure is of vital importance – yet our ability to monitor activity at sea is somewhat more challenging than on land given the vastness of the oceans. Also many maritime monitoring systems rely on ships to ‘opt-in’, that can leave potentially risky blind spots in our picture of maritime traffic. This article, derived from a presentation that David Beard of the Defence Science and Technology Laboratory gave at the recent DMC and NovaSAR International Conference…