Coast Guard Interception Of Homemade Submarine

The USCG has intercepted another DIY Semi-Submersible operated by drug smugglers. CNN tells us:

In the past three months the Coast Guard has learned of more semi-submersible vessels smuggling drugs than it did in the previous six years, when there were 23 cases, officials said.

U.S. Coast Guard intelligence officers predict 85 cases this year and 120 next year.

In some instances, the semi-subs are towed behind other vessels and are scuttled if they are detected, Allen said. Authorities are investigating reports that some semi-subs are unmanned and are operated remotely, he said.

Diplomatic agreements give the U.S. Coast Guard drug-interdiction jurisdiction in partner countries’ waters.

Encounters have become so frequent — and the dangers of boarding the vessels so pronounced — that the Coast Guard is pushing for legislation that would make the use of “unflagged” semi-submersibles in international waters a crime punishable by up to 20 years in prison, even if authorities can’t recover drug evidence because the smugglers scuttle the transports.

“There’s really no legitimate use for a vessel like this,” Allen said.

Earlier this year Eaglespeak and Coast Guard News gave us tour of a similar design:

Despite the cool factor these submarines have one fatal flaw that makes them poor candidates for smuggling efforts. ZeroSix fills us in:

The main problem with real subs is that they are not much more effective than the “semi-submersibles” that are coming out of Colombia (and even Europe). Submarines can only travel underwater, on battery power, for a short time. Otherwise, they are on the surface, or in a “semi-submersible” state, running on diesel power.

The most stunning failure, however, has to be the 100-foot vessel found inside a Bogota warehouse in 2000. The BBC reported:

Police in Colombia say they have found a half-built submarine in a warehouse in a suburb of the capital Bogota.

Police chief General Luis Ernesto Gilibert said Russian documents were found alongside the partially-completed vessel.

He said the 30 metre (100ft) vessel would have been capable of carrying huge quantities of cocaine or heroin.

He speculated that, once completed, the submarine would have been disassembled and taken by lorry to to Colombia’s Pacific or Caribbean coast.

To learn how to build your own submarine check out SubmarineBoat’s Link Page, just make sure to avoid any large ships during the trial run. A warning this NYC artist most likely ignored.

Updated: February 7, 2026 (Originally published March 20, 2008)

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