The last credible post-loss message was heard at 8:18 PM Gardner time on July 7. The Colorado planes were over the island roughly 36 hours later. The Electra's ability to remain intact on the reef depended upon the height of high tide, the amount of wave action on the reef, and the direction of the wave action on the reef. Those factors were not constant. During the week July 2 to July 9 each high tide was getting successively higher. On July 2 the maximum water depth on the reef in the area where we think the plane was parked (assuming a calm sea) was just under half a meter. At high tide the evening of July 7 (about two hours before the last credible transmission was heard) the water level was a bit over .7 meter - again assuming a calm sea. At the next high tide, the water level was nearly .9 meter. We don't know what the sea conditions were but the combination of significantly higher high tide water levels and rougher seas could mean a far more hazardous situation for the plane. We also know that, at times, ocean waves refract around the northwest tip of the island resulting in a southwesterly flow of water over the reef in the area where we think the plane was parked. Surf coming from that direction would drive an object on the reef toward the edge. In short, it doesn't take anything more than normal events for the airplane to have survived relativlkey undisturbed for the first several days and then, quite rapidly, be driven over the reef edge.
A wreck hung up in relatively shallow water in the surf zone could easily be hidden from view on a day like the one pictured in the photo taken during the Colorado overflight but easily visible to someone fishing on the reef edge at low tide on a calm day.