While semi-submersible “narco subs”, which float at or marginally below the surface of the sea, have been used by drug smugglers for about 17 years, the first, long range, fully submersible, technologically advanced “narco” submarine was seized on 2 July 2010 in a mangrove swamp near San Lorenzo, just south of the Columbian border, by Ecuadorian police authorities before its maiden voyage. Capable of carrying between 7-10 tonnes of drugs (with an estimated value of US $100 million for pure cocaine), the diesel electric submarine has a fibreglass hull about 31 metres (102 feet) long, a 3-metre conning tower with periscope and an air conditioning system. A fish-finder device is used as its “eyes” and experts believe it is capable of cruising at 5 knots for extended range at a depth of about 50 feet. Its potential for infiltrating terrorists is also causing concern in law enforcement circles.