Apparently the long-feared appearance of South American “narco-subs” (drug smuggling submersible vessels) in Europe is imminent. This comes from revelations that Israel is deploying new sensors and techniques to find these small, easily built vessels that they fear will be used to attack Israel’s new offshore natural gas fields. Israel is not talking about how they found out.
The United States has been dealing with these vessels for over a decade and is apparently sharing with Israel what it knows about finding these vessels. The Israelis have an advantage in that they have a less restrictive ROE (Rules of Engagement) and, while the United States never has enough surface ships or long-range helicopters to make sure that long-range sensor contacts are actually narco-subs and not some legal vessel, the Israelis can warn all maritime traffic in their coastal waters to identify themselves or risk being fired on from the air or from surface craft. A number of the latter are unmanned, like the new Seagull USV (unmanned surface vessel) that can fire wire guided torpedoes.
Most of these narco-subs are still "semi-submersible" type vessels. These are 10-20 meter (31-62 foot) fiberglass boats, powered by a diesel engine, with a very low freeboard and a small "conning tower", providing the crew (of 4-5), and engine, with fresh air and the ability to safely navigate. A boat of this type was, since they first appeared in the early 1990s, thought to be the only practical kind of submarine for drug smuggling. But since 2000 the drug gangs have developed real submarines, capable of carrying 5-10 tons of cocaine. These subs cost a lot more than semi-submersibles and also don't require a highly trained crew. These subs borrow a lot of technology and ideas from the growing number of recreational submarines being built. Only three of these true subs have been found and apparently they are not sufficiently more effective to justify their higher cost.
Despite losing over a hundred of semi-submersibles to the U.S. and South American naval forces (and dozens more to accidents and bad weather), the drug gangs have apparently concluded that the subs are the cheapest and most reliable way to ship the drugs. Several hundred of these nacro-subs have been built and used on one-way trips to Mexico or the United States. Most of them get through.
A detection network, run mainly by the United States, locates a lot more of these cocaine subs than there are warships available to run them all down. Since the early 1990s the United States has used a special interagency (Departments of Homeland Security, Justice, State, and Defense) and international (over a dozen nations participate) intelligence sharing/analysis operation (Joint Interagency Task Force-South) to track drug smuggling from South America. After 2001 the task force has become quite expert at tracking the submarines and submersibles built in South America for smuggling cocaine to North America and, in a few cases, all the way to Europe. Some of these long range subs are apparently going all the way from Ecuador to the United States, bypassing the Mexican cartels (who have been fighting each other, in a big way, since 2008).
Particularly worrisome are the larger boats headed for Europe. Little is known about these, expect that they exist. Only one has been found, abandoned on a Spanish beach. These subs would be more at risk of being lost because of accident or bad weather than being spotted. European navies (especially Portugal and Spain) and coast guards have been alerted and are looking. Apparently the risk of failure is so high for these trans-Atlantic narco-subs that few have been built and not on a regular basis.
The Colombian security forces and other Latin American navies have been responsible for most of these vessel captures. Usually these boats are sunk by their crews when spotted but the few that were captured intact revealed features like an extensive collection of communications gear, indicating an effort to avoid capture by monitoring many police and military frequencies. The Colombians have captured several of these vessels before they could be launched. Since 2010 the Colombians have been collecting a lot of information on those who actually builds these subs for the drug gangs and FARC (leftist rebels that provide security and often transportation for moving cocaine). That includes finding out where the construction takes place.
Colombian police have arrested dozens of members of gangs that specialized in building submarines and semisubmersible boats. As police suspected, some of those arrested were retired or on active duty with the Colombian Navy (which operates two 1970s era German built Type 209 submarines). These arrests were part of an intense effort to find the people responsible for building subs for cocaine gangs. Find the builders and you stop the building efforts. In this case it has only delayed some construction and made it more expensive to build these boats.