All navigation was done by LORAN-C and was manually recorded. The cruise used the Group Repetition Interval 9930 U.S. East Coast chain and recorded time delays from Cape Race, Newfoundland (X) and Dana, Ind. (Z) slave transmitters. Time delays were manually corrected: +1.2 for X (TD1) and -3.1 for Z (TD2), a distance of about 1.3 km, was applied to the time delays.
Absolute accuracy is 185 to 463 m based on <http://www.navcen.uscg.gov/loran/handbook/h-book.htm> (see Chapter III).