If you can keep yourself from ever being seen by any of those planes, the density will gradually decrease. 30NM is not as far as you think. Some of those planes have hundreds of miles range.
I have played the same mission and got the plane swarm you got. The secret is to stay down ALL day at 2 knots below 100ft. 1 hour after sunset, cruise for a while at deck awash slowest speed while charging. Any sign of aircraft and go deep again for a while. Eventually the traffic will stop and you can high speed it out of there. 1 hr before dawn, go deep again if you are still within 150 miles of Rabaul. Keep this up and you'll be unmolested by planes. All you have to do is get sighted by ONE and the swarm will follow the direction of your last contact for days.
-Pv-
|