3000ft, who say’s so? Read the small print, what about varying depths of water, different runway surfaces, varying wind, touchdown speed, position, etc, etc. What margin then?
From AC 91-79 Runway Overrun Prevention.
10kts fast on a wet runway, 500ft; float due to shearing wind, 2500ft; 10 ft high at threshold 200ft; and these are before you might have to consider a slick runway due to rubber or even hydroplaning.
I said the aircraft could be brought to a halt in 3000ft (i.e. ground run distance) so float and height at threshold do not come into it.
Assuming a correct landing point the total landing distance would be around 4000ft or 50% of what is available hence my comment about a good margin.