--establishes a legal regime applicable to acts against international maritime navigation that is similar to the regimes established against international aviation; --makes it an offence for a person unlawfully and intentionally to seize or exercise control over a ship by force, threat, or intimidation; to perform an act of violence against a person on board a ship if that act is likely to endanger the safe navigation of the ship; to place a destructive device or substance aboard a ship; and other acts against the safety of ships; 9.Protocol for the Suppression of Unlawful Acts Against the Safety of Fixed Platforms Located on the Continental Shelf (1988--applies to terrorist activities on fixed offshore platforms): --establishes a legal regime applicable to acts against fixed platforms on the continental shelf that is similar to the regimes established against international aviation; 10. Convention on the Marking of Plastic Explosives for the Purpose of Detection (1991--provides for chemical marking to facilitate detection of plastic explosives, e.g., to combat aircraft sabotage): --designed to control and limit the used of unmarked and undetectable plastic explosives (negotiated in the aftermath of the 1988 Pan Am 103 bombing); --parties are obligated in their respective territories to ensure effective control over "unmarked" plastic explosive, i.e., those that do not contain one of the detection agents described in the Technical Annex to the treaty; --generally speaking, each party must, among other things: take necessary and effective measures to prohibit and prevent the manufacture of unmarked plastic explosives; prevent the movement of unmarked plastic explosives into or out of its territory; exercise strict and effective control over possession and transfer of unmarked explosives made or imported prior to the entry-into-force of the convention; ensure that all stocks of such unmarked explosives not held by the military or police are destroyed or consumed, marked, or rendered permanently ineffective within three years; take necessary measures to ensure that unmarked plastic explosives held by the military or police, are destroyed or consumed, marked, or rendered permanently ineffective within fifteen years; and, ensure the destruction, as soon as possible, of any unmarked explosives manufactured after the date-of-entry into force of the convention for that state. stupsertod stup1site