Some 2,800 Polish soldiers under Rear Admiral Włodzimierz Steyer, part of the Land Coastal Defence formation, defended the Hel Fortified Area for about 32 days, until they surrenderedb due to low supplies and morale.

Infantry cover for the Hel Fortified Area was provided by a Border Defense Corps (KOP) unit – the Hel KOP Battalion [pl] under Major Jan Wiśniewski [pl] – which had several artillery pieces (four 75 mm, and six 37 mm), sixty-two machine guns, and two large and nine small mortars.

[3] However, Hel also became headquarters for the Polish Navy's commander, Rear Admiral Józef Unrug, who relocated his command center there on the eve of the invasion, on 31 August 1939, concluding that the Hel Fortified Area was better suited to prolonged defense than the more provisional defenses around his peacetime headquarters in Gdynia.

Likewise, the Polish air-defense batteries in the region were too few and too light to deter enemy aircraft, and the Naval Air Squadron's planes tasked with defending the area, stationed at the nearby town of Puck, were both older than their German counterparts and outnumbered by about ten to one.

[3] The second air raid, the same day at 18:00, targeted ships in the port, damaging the Polish light minelayer ORP Mewa.

[12] This effectively eliminated the already heavily outnumbered surface Polish Navy as a fighting force on the Baltic Sea, with only several light units remaining operational in the theater.

[6][13]c The surviving crews of the sunken Polish vessels joined the garrison's defenders, and two 120 mm guns from ORP Gryf were salvaged for shore-battery use.

The Germans, having bottled up the Polish units on the Peninsula, did not launch major land operations until month's end.

In view of German superiority on the Baltic Sea, the remaining Polish naval units docked at the Hel port and their crews joined the ground forces.

[7] Heavier German naval units, namely the old Deutschland-class battleships Schleswig-Holstein and Schlesien, shelled the Hel Peninsula, to little effect.

According to Commager, German forces slowly advanced, still facing substantial resistance and counterattacks, and on 25 September, after the Germans took the village of Chałupy, Polish military engineers detonated torpedo warheads at the Peninsula's narrowest part, temporarily transforming the Peninsula's far end into an island.

The chapter on the Battle of Hel states that no substantial land engagements took place until 28 September, when German units slowly advanced toward Chałupy.

[3] On 1 October 1939 the Polish Navy's commander, Rear Admiral Józef Unrug, taking into account that the Polish outpost was running out of supplies and that no relief force would be coming, and in view of low troop morale, with two mutiny attempts having been quelled on 29 and 30 September,[3] gave orders to capitulate.

[8] Some Polish soldiers attempted to flee across the Baltic Sea to Sweden on the remaining light craft and civilian vessels, but most were unsuccessful.