BRP Dioscoro Papa (PC-381) is the eleventh ship of the coastal patrol boats of the Philippine Navy. It is part of the second batch of its class ordered through US Foreign Military Sales (FMS) in 1993, and was commissioned with the Philippine Navy on 1 June 1995.
It was initially designated as a Fast Patrol Craft, and was numbered "DF-381", but later on was re-designated as a Patrol Gunboat, and was finally re-numbered as "PG-381". Another round of reclassification was made in April 2016, which re-designated the patrol gunboat as the coastal patrol craft "PC-381".
The ship was built to US Coast Guard standards with aluminium hull and superstructure. She is powered by two Detroit Diesel 16V-92TA diesel engines with a combined power of around driving two propellers for a maximum speed of . The vessel's maximum range is at , or alternatively at .
The ship was originally designed to carry one bow-mounted Mk.3 gun, one mortar aft, and four /50-calibre machine guns. Instead, she is armed with one Bushmaster chain gun on a Mk.38 Mod.0 mount, four M2HB Browning 12.7 mm/50-calibre machine guns on Mk.26 mounts, with two positioned forward and two aft; and two M60 7.62 mm/30-calibre machine guns, both mounted amidships. The ship can carry 4,000 rounds of 12.7 mm and 2,000 rounds of 7.62 mm. A large "Big Eyes" binocular is also carried on tripod mounts, one on the forecastle and one just above the mast. As part of the second batch (PG-379 to PG-395), it is equipped with a Mk.38 Mod.0 M242 Bushmaster 25 mm chain gun that the first batch of ships do not carry.
The patrol craft is equipped with a Raytheon AN/SPS-64(V)11 surface search and navigation radar but with a smaller antenna as those used in bigger Philippine Navy ships. Like all other Philippine Navy ships, Dioscoro Papa was fitted with the Philippine Navy Vessel Tracking System (VTS) by the Naval Sea Systems Command.
A rigid inflatable boat powered by a outboard motor is stowed amidships.
On 22 January 1996, Dioscoro Papa (then designated PG-381) was conducting anti-piracy patrols in off the coast of Capones Island, Zambales. During the vessel's patrol it encountered what its crew alleged were naval vessels sporting Chinese bow numbers and flying Chinese flags which were quickly entering Philippine territorial waters. Dioscoro Papas crew reported as having fired warning shots at the vessels, which responded by firing back resulting in a 90-minute gun battle. One of the vessels reportedly attempted to ram Dioscoro Papa, but was foiled due to incurring casualties from Dioscoro Papas gunfire. After incurring crew casualties the vessels fled to the high seas with Dioscoro Papa opting not to pursue due to having depleted its ammunition and fuel during the encounter.
On 11 May 2016, Dioscoro Papa towed ML Rabson back to safety to Tawi-Tawi. Rabson was carrying 120 passengers who had been to Sitangkai town for the elections when it suffered engine trouble, and had been stranded for more than three hours.
In May 2018, Dioscoro Papa participated in the "Third Combined Maritime Security Activity" with the Royal Australian Navy (RAN) along with the , , and . The RAN sent the vessels and for the exercise.