The Drug Trafficking Vessel Interdiction Act of 2008,, was an act of the United States Congress outlawing operation of or travel in unregistered submersibles and semi-submersibles in international waters with the intent to evade detection. The act was enacted to combat the use of illicit self-propelled semi-submersible and submersible vessels in international drug trafficking (see narco-submarine). Notably, the act provides for extraterritorial jurisdiction. The law extended earlier legislation such as the Marijuana on the High Seas Act (MHSA) and Maritime Drug Law Enforcement Act (MDLEA).