You know, there's probably a small enough number of incidents to show the effectiveness of anti-ship missiles with that size warhead or smaller striking naval vessels...
Aw fuck... I'll do it.
November 28th 1980: Iran-Iraq War
> Iranian Missile Boats launched three Harpoon missiles, sinking two Iraqi Osa-II Class Missile Boats (225 tons).
March 24th 1986: Gulf of Sidra Incident
> US Destroyer launches a single RGM-84 Harpoon Missile at a Libyan Patrol Boat, setting it ablaze. It is towed to port.
> US A-6E Intruders fire two AGM-84C Harpoon Missiles at a La Combattante II class Missile Boat, sinking it. (250 tons).
> USS Yorktown fires an RGM-84A and an RGM-84C at a La Combattante II class Missile Boat, sinking or damaging it (250 tons).
> US A-6 Intruder fires a single AGM-84C at a Nanuchka II-type missile corvette, sinking it (670 tons).
April 18th 1988: Operation Praying Mantis
> US Destroyer fired one RGM-84D Harpoon missile and four Standard SAM's at a La Combattante class Missile Boat, crippling it. It was later sunk by gunfire (265 tons).
> US A-6 Intruder fires an AGM-84D Harpoon at the Iranian frigate Sahand after she engaged US Navy warships in the Strait of Hormuz. She was hit aft by the Harpoon and amidships by an AGM-62 Walleye II glide bomb, and forward by an air-launched AGM-123 Skipper II laser-guided missile which crippled it. Another Harpoon missile and a cluster bomb were launched in a coordinated attack by another A-6 and a US Guided Missile Destroyer, sinking it (2500 tons).
Harpoons of the time had the 500lb warheads.
May 4th 1982: Falklands War
> Argentinian Super Etendard's fired two AM39 Exocet missiles at a British type 42 Destroyer. One hit, disabling the vessel. It later floundered and sunk under tow six days later (4200 tons).
May 25th 1982: Falklands War
> Argentine Super Etendard's hit the SS Atlantic Conveyer, a merchant naval ship, with two AM39 Exocet missiles. It was set ablaze due to ammunition aboard. It sank under tow three days later (15000 tons).
June 12th 1982: Falklands War
> Shore launched MM38 Exocet Missile struck a British County-class destroyer, damaging it. Ship was underway again after one day of damage control but too damaged to continue naval operations (6200 tons).
May 17th 1987: Iran-Iraq War
> Iraqi Jet fired two AM-39 Exocets at an OHP-class Frigate. Quick and rapid damage control prevented the Destroyer from sinking. Ship was later repaired and returned to service (4100 tons).
Exocet has a 365 lb warhead.
Sadly
![Stick out tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
it seems the last naval battle with extensive antiship missile action was apparently the 1991 Gulf War.
Look at those little Sea Skua's racking up the kills in the <1000 ton ship class. Not really applicable to discussion here (except maybe after the Chinese navy runs out of surface to air missiles) but still a good watch.