 To address this legal loophole, the US Drug Trafficking Vessel Interdiction Act was enacted in September 2008, making it a "felony for those who knowingly or intentionally operate or embark in a self-propelled semi-submersible (SPSS) that is without nationality and that is or has navigated in international waters, with the intent to evade detection".The penalty is a prison term of up to twenty years in the U.S.The bill does not apply to flagged vessels (i.e., that have been registered with some nation).