Cloud cover
Bad weather that night aided the Continentals. Cloud cover cut off moonlight and high winds forced the British ships in Haverstraw Bay to leave their posts off Stony Point and move downriver. At midnight, as scheduled, the attack began with the columns crossing the swampy flanks of the point. The southern column unexpectedly found its approach inundated in two to four feet of water and required thirty minutes to wade to the first line of abatis, during which it and Murfree's demonstration force were spotted by British sentries and fired upon.