A self-powered semi-submersible vessel carrying four tons of cocaine was caught off of Mexico’s Pacific coast, said Customs and Border Protection.

The vessel was not a true submarine, as it was not entirely underwater. Instead, it operated mostly underwater, helping keep the rest low to the surface and therefore being harder to catch.

That did not stop CBP Air and Marine Operations from catching it. A crew in a Lockheed P-3 Orion surveillance plane spotted the 85-foot-long vessel in waters southwest of Mexico.

“The P-3 Aircrew detected, tracked, and led the interdiction of this SPSS by one of our partners.  This seizure kept over 84 million dollars in illicit proceeds from going to transnational criminal organizations,” said National Air Security Operations Center – Corpus Christi Director of Air and Marine Operations Marshall Dillon.

Authorities arrested five suspects and seized 8,232 pounds of cocaine valued at more than $84 million. CBP did not specify any nationality or demographic information regarding the suspects.

• Brad Matthews can be reached at bmatthews@washingtontimes.com.