Currently (16:00 CET), there are three USN Boeing P-8As engaged in missions in the Mediterranean/Black Sea area.
Two P-8As are returning to NAS Sigonella: the first after conducting a surveillance mission along the shores of the Black Sea (where it also refueled from a USAF Boeing P-8A), the second returning after completing a surveillance mission off the coast of Syria and Lebanon.
The third Poseidon is in turn heading towards the Black Sea, where, as evidenced by this rotation, NATO presence is practically continuous.