It also occurred to me that if I'm trying to find one of those islands, the higher I fly the better
my odds of seeing one. Cloudy conditions around the Howland position (and especially to the
Northwest-the reason the initial Itasaca search went thataway) may have led Noonan to
conclude that moving to the southeast not only would provide many more (and more easily seen)
landing targets, but very well get him into clear sky conditions and thus allow a high altitude search, which would have greatly improved his chances of seeing land, any land.
There are also the problems of seeing anything in the direction of the low-lying sun. My experience is that when you're looking in the direction of the sun in the morning, good luck seeing anything. At a higher altitude, the sun becomes less of a problem. All this argues against the assumptions made in the search box hypothesis, namely that one can see an island a certain number of miles away, from a low altitude, regardless of viewing direction. That certainly isn't the case. Personally, I would guess that Noonan had had enough experience in finding land targets visually to know what conditions would give him the best odds.
Since all of us presumably believe he landed on Gardner island, we have to agree that Noonan succeeded
in achieving his most important goal : finding land. Any,land. And land that had a beached ship sitting right on the shore, which implied human habitation.