As the German advance closed in, tension rose steadily among the Allied troops. The enemy was expected at any moment, and the final preparations for battle were hurriedly completed. Overhead, the Luftwaffe became increasingly active, foreshadowing the fighting that was about to engulf the sector.
Elements of the French 60th Infantry Division had arrived and were ordered to relieve the regiments of the 68th Division holding the canal positions. These last-minute redeployments took place under the watchful eyes of an enemy that enjoyed near-complete air superiority, adding further strain to an already precarious situation.
The Zanddijk Line witnessed considerable troop movements as a result of the revised French operational directives. Units of the 68th Infantry Division were gradually relieved by those of the 271st Infantry Regiment of the 60th Infantry Division. The incoming troops took over the foxholes and defensive positions west of the canal, while only a few motorised elements of the 68th Division remained on Zuid-Beveland.
The 271st Infantry Regiment was reinforced by two battalions of 75 mm artillery from the French 307th Artillery Regiment, a company of engineers, two anti-tank batteries, and the battery of six 25 mm anti-aircraft guns that had previously been deployed at Flushing. Overall command of the force rested with Colonel Guihard. The transfer of responsibilities and positions would not be fully completed until the afternoon of 14 May.
Meanwhile, the exposed Dutch troops of the 3rd Battalion, 40th Infantry Regiment, who had been ordered by General Durand to occupy positions along the northern coast of Zuid-Beveland, endured repeated attacks and harassment from the Luftwaffe. German bombers and fighters, ranging freely across the island in search of targets, repeatedly bombed and strafed the troops as they attempted to establish their improvised defensive line. Apart from machine guns, the battalion possessed virtually no proper means of defending itself against air attack.
Morale, already shaken by the abandonment of a well-prepared defensive position in favour of one that scarcely existed, deteriorated further. The men were exhausted from a lengthy march, and the demands of preparing new positions under constant aerial threat stretched them to the limit. The situation was compounded by persistent rumours of German airborne landings. Repeatedly, the troops were ordered to conduct sweeps through the surrounding countryside in search of these supposed enemy forces.
Almost any unusual sight- a bursting anti-aircraft shell, a small cloud formation, or even a flock of birds - could trigger fresh reports of parachutists. Such reports were invariably followed by yet another search operation, all of which proved fruitless. The psychological impact of this new form of warfare was profound. For these poorly trained troops, the constant threat from the air, combined with rumours of enemy parachutists appearing anywhere and everywhere, steadily eroded morale and drained their already limited reserves of energy. Yet despite the tension and exhaustion, no enemy was actually in sight - at least not on the ground.
The Dutch 109th Anti-Aircraft Battery, positioned behind the Zanddijk Line, had been in action since the opening hours of the campaign. A seemingly endless stream of German aircraft passed overhead each day on their way to and from Walcheren. The battery's three ageing 75 mm anti-aircraft guns, lacking modern fire-control equipment, had nevertheless remained undetected thanks to excellent camouflage and careful concealment. That fortunate situation was about to come to an end.
At approximately 1000 hours, a Kette of Heinkel He 111 bombers launched a direct attack on the battery's position. Flying at extremely low altitude, the bombers dropped more than two dozen 50-kg bombs before returning to strafe the emplacement. The defenders were largely powerless to respond. Apart from two heavy machine guns, they possessed no effective means of engaging aircraft at such close range, as their anti-aircraft guns required a minimum firing distance of approximately 1,000 metres.
The battery's well-prepared defensive works proved their worth. Despite the intensity of the attack, only a single soldier was killed during the raid. The principal consequence of the assault was not casualties, but the loss of the battery's concealment. Its position had been identified, making continued occupation hazardous.
As a result, the battery commander ordered a move to an alternative location. The relocation was carried out during the night. The battery would consequently be unable to participate in operations the following day, as the commander insisted that the new position be thoroughly camouflaged before the guns resumed firing.
Along the Bath Line, the Dutch defensive position closest to North Brabant, the fourth day of the war brought the unmistakable sounds of an approaching ground campaign. In particular, the distant thunder of German heavy artillery operating around Moerdijk and further west made it clear to the defenders that the enemy was steadily drawing nearer. The growing sense of anticipation prompted frequent reconnaissance patrols westward, while tension throughout the line continued to mount.
A detachment of railway troops received orders to demolish the railway line that crossed the Bath Line. Only days earlier, these same men had laboured tirelessly to repair the track after it had been damaged by German air attacks. Now they were required to destroy their own work in preparation for the enemy's advance. For many, the order was a deeply discouraging one.
German aircraft continued to strafe and bomb the defensive positions. Despite the considerable Luftwaffe activity over the Bath Line, the attacks caused only limited casualties. Four soldiers were wounded, while no fatalities were reported.
A renewed stream of retreating Dutch troops - and the occasional French soldier - continued to arrive from the east, although in smaller numbers than on previous days. Their appearance nevertheless had a detrimental effect on morale. Many of these men had already experienced combat at several different positions and bore clear signs of exhaustion and strain. Their stories of German strength and battlefield success left a profound impression on the soldiers of the 14th Border Infantry Battalion.
By the end of the day, morale along the Bath Line had reached a low point. The men in the trenches waited anxiously for what lay ahead. Most were convinced that the following day would bring them face to face with the enemy. The war, which until then had largely been experienced through the accounts of others, would soon become a matter of personal experience against an opponent whose reputation inspired both respect and apprehension.