Here's a hint for those that came in after intermission:
https://www.bibliotecapleyades.net/antarctica/antartica11.htm
Operation Highjump overview; Admiral Byrd in Antarctica. German submarines type 21 and 23 could use the snorkel telescoping tube, along with the Walter motor using hydrogen peroxide fuel for ranges up to 30k miles. They knew the underwater way to get into the base.
Here's a hint for those that came in after intermission:
https://www.bibliotecapleyades.net/antarctica/antartica11.htm Operation Highjump overview; Admiral Byrd in Antarctica. German submarines type 21 and 23 could use the snorkel telescoping tube, along with the Walter motor using hydrogen peroxide fuel for ranges up to 30k miles. They knew the underwater way to get into the base.