Battle of Hel The Battle of Hel was one of the longest battles of the Invasion of Poland during World War II . The Hel Peninsula , together with the town of Hel , was the pocket of Polish Army resistance that held out the longest against the German invasion . Approximately 3 , 000 soldiers of the Fortified Region Hel unit ( " Helski Rejon Umocniony " ) , part of the Coastal Defence Group ( " Grupa Obrony Wybrzeża " ) under Capt . Stanislaw Zwartynski , defended the area against overwhelming odds from 9 September until 2 October 1939 , when they surrendered . Prelude . There was a Polish military port in Hel from 1928 , and the Polish military had been in control of the northern part of the peninsula since the 1920s . In 1936 the northern section of the Hel peninsula was officially named Hel Fortified Area ( " Helski Rejon Umocniony " ) . Approximately 3 , 000 soldiers were stationed in the area , and the Fortified Region included three coastal ( anti - ship ) and anti - air gun batteries . The coastal batteries were divided into one 4 x 152 mm battery , two older 2 x 105 mm batteries and three batteries with 8 x 75 mm guns in total . Anti - air batteries had 6 x 75 mm and 8 x 40 mm guns , and two 120 cm searchlights . The battle . Hel was the target of Luftwaffe air attacks from the first day of the invasion ( 1 September ) . Hel defenders damaged a German destroyer on 3 September . Several Polish light minelayer s laid a minefield near Hel in the night of the 12th and 13 September . After some of the Polish ships were sunk by the Luftwaffe on the following day , and due to German control of the Baltic Sea , the remaining Polish naval units docked at Hel port and their crews joined the ground forces . The ships ' armaments were stripped and converted into additional land gun emplacements . German naval units , including old battleships " Schleswig - Holstein " and " Schlesien " , shelled the Hel peninsula from 18 September , but with little effect . " Schleswig - Holstein " was lightly damaged by Polish coastal batteries on 25 September . Hel anti - aircraft batteries proved to be extremely efficient , shooting down between 46 and 53 German aircraft during the battle . By 14 September Polish forces on the Hel peninsula were cut off from the mainland . After initially being stalled by Polish defences , the Germans brought land artillery batteries and an armored train battery to support their barrage . German forces slowly advanced , although they were still facing significant resistance and counterattack s . On 25 September , after Germans took the village of Chałupy ( today part of the town of Władysławowo ) , Polish military engineers detonated a number of torpedo warheads in the narrowest part of the peninsula , and for a time separated the peninsula from the mainland , transforming it into an island . On 1 October , the commander of the Polish Navy , counter - admiral Józef Unrug , taking into consideration that the outpost was running out of supplies and that no relief force would be coming , gave the orders to capitulate . The Germans occupied the peninsula by 2 October . After the capitulation of Hel , the only organized Polish resistance was carried out by Independent Operational Group Polesie , eventually capitulated at the end of the Battle of Kock .