I'm in the Arctic Ocean and tracking PQ17 (GWX) with the Mission Editor...in other words, I'm cheating big time

. The convoy has been attacked by the Luftwaffe and all the escorts have scattered for home...leaving a very big convoy defenseless. The merchants are just East of Bareninseln and heading ENE towards Hopen island.
The problem I'm running into is the difference in the 2 "rulers"...the SH3 game map shows the distance from Bareninsel to Hopen as 712 km and the ME map gives the distance as 374 km??
What gives?