Cmdr. Gerald L. Ketchum, USN
Burton Island used her four-bar single-circle postmark (figure 1) throughout the expedition. Two straight-line ship's name rubber stamp markings appear quite regularly on the reverse of Burton Island mail from Highjump (figures 2,3).
A three-line rubber stamp reading, "NAVY ANTARCTIC / EXPEDITION / OPERATION HIGHJUMP" (figure 4) has been seen on some Burton Island covers. This is believed to be of private origin and never used by Highjump personnel.