Gregorio del Pilar also has two 3,500 horsepower (2,600 kW) Fairbanks-Morse[2] diesel engines, capable of driving the ship economically at 12 knots (22 km/h; 14 mph) for up to 12,500 nmi (23,200 km; 14,400 mi) without refuelling.

[13] The Philippines reportedly ordered at least four new Mk.38 Mod 3 25mm naval guns, and are expected to be installed on all Gregorio del Pilar class ships.

A BO-105 light surveillance helicopter was initially assigned to the ship, and was replaced by the AgustaWestland AW109 Power, which made its first official shipboard deployment on May 21, 2014.

Among those to be acquired are new Combat Management System (CMS), Hull Mounted Sonar (HMS), and a Radar Electronic Support Measures (R-ESM).

In 2020 October 14, Navy chief Giovanni Carlo Bacordo revealed the completion of the 3D modeling program for the entire ship class' cabling systems to be used for their electronic upgrades (CMS + 4 sensors).

From 1965–1975, Hamilton served on Atlantic Ocean Stations, collecting valuable oceanographic data and conducting frequent search and rescue missions.

In 1994, Hamilton received the Coast Guard Meritorious Unit Commendation for rescuing 135 Haitians from the sea after their sailboat capsized and sank.

In 1996, Hamilton transited the Panama Canal and served as the command and control platform for Operation Frontier Shield, a multi-agency effort to curtail the influx of narcotics into the United States.

Hamilton frequently patrolled the Bering Sea off the Alaskan coast at the Maritime Boundary Line (MBL) which separates the Russian and the United States' Exclusive Economic Zones (EEZ).

[24] Proposal to decommission USCGC Hamilton from the US Coast Guard was made for fiscal year 2011 budget, and the Philippines sent a formal letter of interest for its purchase.

In return, the US Coast Guard began procuring and installing the safe-to-sail navigation equipment, radar systems and additional electronics that the Philippines requested as part of its transfer support case.

[25] Its maiden voyage included a port visit to Hawaii and docking at Alameda, California to finish the remaining work, with around 13 separate contracting actions.

[32][33] BRP Gregorio del Pilar (PF-15) was formally commissioned by the Philippine Navy on December 14, 2011, at Pier 13, Manila South Harbor.

[35] President Aquino hoped that this, his first major military acquisition, would be a symbol of his administration's intention to strengthen and modernize the Philippine Navy and the Armed Forces, and to defend its territory and Exclusive Economic Zone (EEZ) in the South China Sea.

[33][36] BRP Gregorio del Pilar was involved in a standoff in 2012 at the Scarborough Shoal when it tried to apprehend eight Chinese fishing vessels in the island.

[37][38][39][40] BRP Gregorio del Pilar was also one of the naval vessels that the AFP Western Command sent to help in the searching efforts for Malaysia Airlines Flight 370.

[42] After touring the ship, he announced that a third Hamilton-class cutter similar to Gregorio del Pilar (USCGC Boutwell (WHEC-719)) and the research vessel RV Melville will be turned over to the Philippine Navy.

[51] On July 30, 2011, Gregorio del Pilar and USS Reuben James conducted a Passing Exercise (PASSEX) off the coast of Hawaii.

[53] Gregorio del Pilar, together with BRP Rajah Humabon participated in the sea phase exercises with the US Navy during the Balikatan 2013 from April 5 to 17, 2013.

[54] The ship conducted an offshore visit at Lingayen, Pangasinan during the city's "Pistay Dayat 2013" ("Feast of the Sea 2013"), with an open house tour and rescue exhibition exercises performed by the crew.