For obvious reasons, Earhart’s strip map and navigational instructions for the trip to Howland are not available for inspection. However, charts for the same flight, prepared by Clarence Williams on February 9, 1937 but from the opposite direction, are now in the Special Collections archive at Purdue University in West Lafayette, Indiana. These show a great circle route representing the shortest distance, 2,556 statute miles (2,223 nm), between the two points, based upon 16 way points.¹ Williams uses the position of 0°49′N, 176°43′W for Howland, the accepted position at the time, corresponding to 2219 nm along a great circle route. CDR W. N. Derby, USCG, commanding officer of the Itasca in 1935, had already sent a letter to the Naval Hydrographic Office detailing the latest, accurate, position for Howland as 0°50′30″N, 176°34′30″W.² On Aug. 17, 1936, William Miller, in his 6th Equatorial Cruise Report, reported that a revised position of Howland was determined to be 0°48′6″N, 176°38′12″W.³ A copy of this cruise report was retained by Bill Miller for his office files, and he undoubtedly had access to this information when conferring with Earhart prior to her departure. Whether he gave her the latest position information for Howland is unknown. The distance from Lae to this revised, corrected, location for Howland is 2223 nm. The difference in positions for the various Howland locations are on the order of 5 nm, an insignificant amount should one come upon visual range of the island itself.

The route from Lae to Howland passes over or near land at only four locations:

1. The southern coast of New Britain, about 200 nm after departure.
2. The northern tip of Bougainville, in a natural near sea-level saddle between two mountain peaks about 450 nm out.
3. The uninhabited Nukumanu Islands about 735 nm out.
4. The island of Tabiteuea in the Gilberts, about 1,700 nm out.

There is no evidence to suggest that Earhart’s intended route from Lae to Howland Island was anything but the reciprocal of the original plan. The magnetic variation along the route varies from 6 to 9 degrees East from Lae to Howland.⁴ Independent verification of magnetic variations during this time period indicate no errors on the part of Clarence Williams. Earhart would begin her flight steering a 73° magnetic (80°True) course, changing over to 68° magnetic (78°True).

As a safety measure and navigational aid a U.S. Navy ship, the U.S.S. Ontario, was stationed at approximately the halfway point on the great circle route at 3.9°S/165.6°E, some 1,104 NM from Lae. The USS Ontario was to help guard Earhart’s plane and to collect weather information from the surrounding area and to provide that information to the Fleet Air Base, Pearl Harbor, so that accurate forecasts could be provided to Earhart. Standing by at Howland Island was the U.S. Coast Guard Cutter Itasca.