An unusual maritime drone was discovered floating upside down in Romanian waters on April 3 2024. The new type of uncrewed surface vessel (USV) was actually based on an American built rescue boat, modified as a drone. It was equipped with a large warhead indicating that it was designed to hit ships or other naval targets.
Romanian forces reportedly destroyed the boat in a controlled explosion on April 5. The events were not publicized initially and few details were revealed when it was later shared in local media. However an analysis of the vessel answers the questions of what it is, yet raises new questions.
The USV uses an AM-800 aluminum-hull rigid inflatable boat (RIB). This is produced by Silver Ships in Alabama, United States. The boat is designed for fire rescue or as a maneuvering target and the original red finish is still visible on the lower hull and inflatable collar.
The AM-800 is around 9.5 meters (31 feet) long including the outboard motors. While still small, this makes it nearly twice the length of the Magura and Sea Baby USVs Ukraine is using. The RIB is likely to be seen from further away. Its powerful warhead may make up for this.
Powerful warhead from Styx missile
The warhead is from a P-20 Styx anti-ship missile. This is a Soviet-era weapon and, while still in service in Russia, is generally viewed as obsolete. It has a noticeably powerful warhead though, it’s main merit. Both Russia and Ukraine likely have easy access to this type of warhead.
The warhead is mounted on a crude wooden frame in the forward deck of the boat. It is a ‘4G20′ model which is associated with P-20 export model variants of the Styx missile. It weighs just under 500kg (1,100lb) of TGAG-5 explosives which is 60% TNT, 20% RDX, 15% aluminum powder and 5% phlegmatizing wax. For context, this is over twice the size of the Harpoon anti-ship missiles’ warhead.
Interestingly, the Houthi Movement has also used this type of warhead on some of its explosive USVs. The Houthi’s had access to these warheads from legacy Yemeni Navy stocks so there is no suggestion of a direct link to this new vessel.
The warhead has a shaped charge at the front to punch a large hole in the ship before the main charge detonates, thus causing more damage. This is described as a high-explosive-cumulative charge. In the missile the shaped charge is facing slightly downwards to cause maximum damage. On the USV however it is desirable to direct the shaped charge directly forward, so the whole warhead has been mounted at an angle. While the stand-off detonation from the USV is less desirable than the penetrating hit of the missile, the size of the warhead makes this USV formidable.
Attribution: Whose is it?
The nationality of the vessel was not shared officially, although some local media suggested that it is Ukrainian. The nature of the vessel, and being based on an American hull, does support this conclusion. The manufacturer, Silver Ships, had previously been reportedly supplying unspecified craft to Ukraine as part of U.S. Aid. So it seems most straightforward that it is Ukrainian. It possibly capsized further north and drifted to where it was found.
However the possibility that it could be Russian should be seriously considered. Russia has tried to disrupt or prevent merchant ships sailing to Ukraine since the end of the Black Sea Grain Initiative last July. Efforts have focused on attacking Ukrainian port infrastructure, but air-dropped mines have also been used. This is likely because mines are more deniable than using warships or missiles.
However the mines have been unsuccessful so far, with some Ukrainian sources suggesting that the Russians are now unable to sow them. Therefore Russia may be tempted to use USVs to hit ships, thus reestablishing a de facto blockade. Although it may be clear which country is doing it, the USVs would still be deniable. It is likely that Russian propaganda would blame Ukraine to create enough ambiguity to avoid immediate consequences.
Whether this USV was Ukrainian (which seems most likely) or Russian may be revealed in due course. But the likelihood of both sides operating USVs in the Black Sea is increasing so a Russian craft is bound to turn up sooner or later.
