All vessels on the high seas should carry identification numbers and be trackable using satellite or other technology, says the Global Ocean Commission, an independent high-level initiative on the future of the ocean.
Currently, passenger ships and large merchant vessels have to carry unique and unchangeable International Maritime Organization (IMO) numbers, and to operate equipment allowing real-time tracking.
But other craft on the high seas - the international waters that make up nearly half of the planet's surface - do not. The UN has previously noted that this facilitates trafficking of people, drugs and weapons, and illegal fishing.
'In the 21st Century, when governments are doing so much to make their borders and their citizens secure, it seems extraordinary that they've left a loophole big enough to sail a trawler full of explosives through,' said former Costa Rican President José María Figueres, who jointly chairs the Global Ocean Commission with Trevor Manuel, Minister in the South African Presidency and David Miliband, the former UK Foreign Secretary and incoming President of the International Rescue Committee.
'There are details to be worked through, such as the cost of tracking systems, although from evidence we've heard so far we don't think that will be an obstacle. 'But in principle, for the security of citizens around the world, it seems clear that it's time to close the loophole.'
Following the Mumbai bombing in 2008, which used a fishing vessel hijacked on the high seas, Indian authorities made tracking equipment mandatory on fishing vessels and other craft in their national waters. Many other countries are also implementing its use.
The Global Ocean Commission is an independent initiative aiming to halt and reverse degradation of the global ocean, and restore it to full ecological health.