"Fairly small gunboats" don't have helicopter decks. They also don't survive a Silkworm strike.
Eilat (Saar V) class large missile corvettes
Displacement: 1,275 tons full load
Dimensions: 86.4 x 11.9 x 3.2 meters (283.5 x 39 x 10.5 feet)
Propulsion: 2 shafts; 2 cruise diesels, 6,600 bhp, 20 knots; 1 LM2500
boost gas turbine, 23,000 shp, 33 knots
Crew: 74
Aviation: aft helicopter deck and hangar; 1 Dauphin helicopter
Radar: TPS-44 3-D air search
Sonar: Type 796 hull, towed array
Fire Control: 2 M-2221
EW: NS 9003 intercept/jammer, 4 SRBOC, SLQ-25 Nixie
Armament: 8 Harpoon SSM, 64 VL Barak SAM, 1 20 mm
Phalanx CIWS, 2 20 mm AA, 2 triple 12.75 inch torpedo tubes
Heavily armed multirole corvettes, built in USA.
Combat systems fitted in Israel after delivery. Some
planned weapons were not installed due to topweight problems.
Can serve as 'leaders' for smaller FACs.
Number Name Year FLT Homeport Notes
501 Eilat 1994 MED Haifa
502 Lahav 1994 MED Haifa
503 Hanit 1995 MED Haifa
If this was a Silkworm strike, I've got to think the CIWS wasn't activated, and that the Israelis didn't foresee this threat.
Eilat class corvette(No Phalanx CIWS visible, may not have been installed as per your description)
heavily-armed Saar-4.5 Hetz/ Nirit Class missile boat (Phalanx CIWS Very visible At the bow)
Or the CIWS failed to hit it until it was just a few yards out.
"I've got to think the CIWS wasn't activated, "
Does this mean the phalanx system wasn't turned on? Why wouldn't they keep that on all the time?