▁Robin ▁Mo ors ▁passengers ▁and ▁crew ▁were ▁allowed ▁thirty ▁minutes ▁to ▁board ▁lif eb o ats , ▁then ▁the ▁sub marine ▁tor ped o ed , ▁sh elled ▁and ▁s ank ▁the ▁ship . ▁The ▁surv iv ors ▁then ▁dr ift ed ▁without ▁rescue ▁or ▁detection ▁for ▁up ▁to ▁eigh teen ▁days . ▁When ▁news ▁of ▁the ▁s inking ▁reached ▁the ▁US , ▁few ▁sh ipping ▁companies ▁felt ▁truly ▁safe ▁anywhere . ▁As ▁Time ▁Magazine ▁noted ▁in ▁June ▁ 1 9 4 1 , ▁" if ▁such ▁sink ings ▁continue , ▁US ▁ships ▁bound ▁for ▁other ▁places ▁remote ▁from ▁fighting ▁front s , ▁will ▁be ▁in ▁danger . ▁Hence for th ▁the ▁US ▁would ▁either ▁have ▁to ▁recall ▁its ▁ships ▁from ▁the ▁ocean ▁or ▁en force ▁its ▁right ▁to ▁the ▁free ▁use ▁of ▁the ▁se as ." ▁In ▁October ▁ 1 9 4 1 , ▁federal ▁pro sec utors ▁in ▁the ▁esp ion age ▁case ▁against ▁a ▁group ▁of ▁ 3 3 ▁defend ants ▁known ▁as ▁the ▁" D u ques ne ▁Sp y ▁Ring " ▁ad du ced ▁testim ony ▁that ▁Leo ▁Wa alen ▁had ▁submitted ▁the ▁sail ing ▁date ▁of ▁Robin ▁Mo or ▁for ▁radio ▁transmission ▁to ▁Germany , ▁five ▁days ▁before ▁the ▁ship ▁began ▁her ▁final ▁voyage . ▁Wa alen ▁was ▁found ▁guilty ▁and ▁sent enced ▁to ▁ 1 2 ▁years ▁in ▁prison ▁for ▁esp ion age ▁and ▁a ▁concurrent ▁ 2 - year ▁term ▁for ▁viol ation ▁of ▁the ▁Foreign ▁Ag ents ▁Reg istration ▁Act . ▁ ▁U -