BRP Ladislao Diwa (PS-178) is an Alvarez-class patrol ship of the Philippine Navy.

Launched as the ninth of fourteen ships of the Cyclone-class patrol ship, the primary mission of USS Chinook (PC-9) was to serve as a platform for conducting maritime special operations, including interdiction, escort, noncombatant evacuation, reconnaissance, operational deception, intelligence collection, and tactical swimmer operations.

Her small size, stealthy construction and high speed were tailored to performing long-range Special Operations Forces (SOF) insertion and extraction as well as other SOF support duties as needed.

On 10 January 2023, Chinook, along with sister patrol ship USS Monsoon (PC-4) and guided-missile destroyer USS The Sullivans (DDG-68), stopped and boarded a fishing vessel in the Gulf of Oman that was smuggling over 2000 AK-47 assault rifles.

[2][7] She was rechristened as BRP Ladislao Diwa (PS-178) on 11 September 2023, in honor of a Filipino revolutionary in its war of independence from Spanish colonial rule.