Depending on when you read this next showing slated for: Dec 27th [Sat] in the afternoon (click link to show ALL upcoming episodes if looking at list not just the default primetime only airings). link to episode info page on Nat Geo: http://channel.nationalgeographic.com/channel/episodes/cocaine-sub-mystery/ Columbian Narco Subs Most were only wem-submersible, this episode follows law enforcement as they attemppt to hunt down the first known FULLY submersible Cocaine Sub. First we hear about how Columbian Drug Lords started by using speed boats that could get to shallower water and move faster than most Coast Guard ships. The Coast Guard Responded by using 50 caliber sniper rifles to incapcitate speeding boats (by hitting the engine usually). Drug Runners responded with the first semi-submersible drug subs that instead of favoring speed favor stealth. Officials have noticed in recent years. They start by renting a boat, and getting in contact with an informant in Columbia which helps to build the Drug Subs which cost roughly $1 Million USD, and takes about 4 months to construct. These subs are built along Columbia's pacific coast in the Mangrove swamps. After they send the informant to tag the boat's construction site they lose contact after a day during which the GPS tag on the informant showing him going out to sea. The second day they were waiting for contact with the informant they went to scope out past seized semi-submersibles at the Coast Guard station in Tumaco. The boats can normally hual 6 to 7 tons of Coke with 4 crew members in a 70ft space (with only about 10x10 ft of space for the crew), junk food, sleeping in shifts and always wary of rough seas which can capsize them. The Drug Subs design originated with a man code named Captain Nemo who is currently in prison, but his design has lived on and being constantly improved. We then get to see aa third Drug Sub that was captured in a fully working condition. They find out the subs use a sophisticated exhaust system to transfer the heat to the sea, along with, a newer marine engine which gives it a 3,000 mile range. We then hear Drug Sub designs have dropped from random and varied per sub down to 2 to 3 different designs. the third day is passing now and the informant still has not been heard from. By that night the officers finally get word from their informant. He was too scared to actually tag the boat, but they get him to try one more time early the next morning. The next morning the marines are out looking for more Drug Subs and their construction sites with a 2nd team of Columbian Marines with another American operative consulting with them. They head in to the jungle continuing their search not finding much aside from a small village where they attempt to gather information. After that we are shown a "Base Lab" while the team was trying to find an "HCL Finishing Lab" they still take the time to burn the lab down while explaining it's operation beforehand. Next, we hear of the Coast Guard and Mariens have tried to counter act these Drug Subs wiith a new vessel named the Stiletto that can operate in very shallow water. It uses stealth itself and has quite a sophisticated suite of technology to aid the troops in their work. Even though this has shown to be a good start it is still a test ship under desgin changes. It also lacks things like bunks or a galley so it can not stay out on multi day missions either. This new boat also has not as of yet caught a Drug Sub on the water. Cut to we hear from the informant and he apparently got scared again and did not tag the boat, further, the officers hear that the boat they were hoping to find under construction has made it out to sea making it near impossible to find. The show moves on to another target which is a fully submersible Drug Sub they have located after 6 months of searching for it. Then we finally get to see a fully submersible Drug Sub found in the jungle in a construction site. Even though it had not been placed in to the water it was fully operational. It's interior shows that they have gotten a lot more advanced there is a lot more space and some sophisticated electronics. They discuss the possibility of a foreigner with advanced sub construction knowledge was probably involved with this sub's construction. (thetvdb.com)