90% of the vessels go undetected - truly remarkable that there has not been any desire to change the way that they engage with the threat to the porous coastline.

This can only be chocked up to the inertia of bureaucracy and the lack of any real concern for the health of Americans.

At least $1billion worth of cocaine has been seized from 'narco subs' en route to the US in the last eight years, DailyMail.com can reveal.

But anti-smuggling commanders believe around nine in 10 boats evade detection, meaning up to $9 billion worth of the drug may have entered the country via these vessels.

Criminal gangs are increasingly using drug-laden semi submersibles to transport vast quantities of illicit substances into the US as they seek to outwit maritime police.

The boats, which are not fully submersible but can dip under water like submarines, have advanced significantly in recent years.

One former cartel member has predicted that missions, previously considered 'kamikaze rituals' for crews, will soon be run by drug traffickers using remote controls from the safety of their headquarters.

It comes after a Colombian man dubbed the 'Prince of Submersibles' was jailed in the US for more than 20 years for running a fleet of narco subs shipping cocaine into the country.

Official data on the number of narco-subs smuggling drugs into the US is yet to be released, but an audit of publicly available U.S. Coast Guard busts by DailyMail.com has found at least $1billion worth of cocaine has been seized from these boats since 2015.

Given that the audit was only of cases already made public, the real figure is likely to be much higher.

Maritime police insist they are getting better at intercepting the boats, but operation commanders have compared scouring the open ocean for 20 foot semi-submersibles to a pair of police cars patrolling the entire country.

I gotta admit this is pretty creative - makes you feel like you're in the wrong line of business.

EXCLUSIVE: Inside the hunt for 'narco subs' smuggling billions of dollars of drugs into the U.S: At least $1BN of cocaine has been seized in past decade - but experts say 90% of the vessels go undetected

At least $1billion worth of cocaine has been seized from 'narco subs' en route to the US in the last decade, DailyMail.com can reveal.

^{By Miles Dilworth, Senior Reporter For Dailymail.Com (Daily Mail)}