Something like 300-500yds travel before the proximity fuses arm. When shooting off the starboard fantail at a low target/pt boat the AA rounds detonate harmlessly over friendly pt boats who are spawning, or over aircraft that are lining up for takeoff or in the slot to land.
This is detrimental to the planes flying from the flattop. A few times last night I was on final, probably 400yds from touchdown when an AA round went off right in my face. Needless to say I splattered all over the fantail
