Around the time many of you were posting of your Thursday night (3/18) sightings, I was on the porch here in Seagrove overlooking the beach. 2 helicopters flew over at a rather low altitude; I couldn't tell what they were becuase there was no moonlight, and the first chopper had no lights on whatsoever; I couldn't even see any instrument panel lighting; the second chopper was lit as usual. I couldn't make out what type they were; looked to be about the size of Chinooks but didn't quite sound like the double=prop sound I'm used to.