It was initially designated as 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".[1] 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 2,800 hp driving two propellers for a maximum speed of 28kn. Maximum range is 1200nmi at 12kn, or alternatively 600nmi at 24kn.
The ship originally designed to carry one bow Mk.3 40 mm gun, one 81 mm mortar aft, and four 12.7 mm/50 calibre machine guns. Instead, she is armed with one 25mm Bushmaster chain gun on 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 caliber 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 25mm chain gun that the first batch of ships do not carry.[3]
She 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.[2] Like all other Philippine Navy ship, she was installed with the Philippine Navy Vessel Tracking System (VTS) by the Naval Sea Systems Command.[4]
A 4-meter rigid inflatable boat powered by a 40-hp outboard motor is stowed amidships.[5]
On 22 January 1996, BRP Dioscoro Papa (then designated PG-381) was conducting anti-piracy patrols in off the coast of Capones Island, Zambales. During its 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. PG-381's 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 the Dioscoro Papa, but was foiled due to incurring casualties from the Dioscoro Papa's gunfire. After incurring crew casualties the vessels fled to the high seas with the Dioscoro Papa opting not to pursue due to having depleted its ammunition and fuel during the encounter.[6] [7] [8]
On May 11, 2016, the BRP Dioscoro Papa towed the M/L Rabson back to safety to Tawi-Tawi. The M/L 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 when the BRP Dioscoro Papa found it.[9]
In May 2018, the BRP Dioscoro Papa participated in the Third Combined Maritime Security Activity with the Royal Australian Navy (RAN) along with the BRP General Mariano Alvarez (PS-38), BRP Anastacio Cacayorin (PC-387), BRP Cebu (PS-28) and BRP Filipino Flojo (PC-386). The RAN sent the vessels HMAS Albany (ACPB 86) and HMAS Glenelg (ACPB 96) for the exercise.[10]