Four hundred mounted troopers were, moreover, stationed in the town of Tholen, while the little fleet, which had been prepared at Antwerp; lay near that city ready to co-operate with the land force as soon as they, should complete their enterprise.

The Grand Commander now divided the whole force into two parts: One half was to remain in the boats, under the command of Mondragon; the other half, accompanied by the two hundred pioneers, were to wade through the sea from Philipsland to Duiveland and Schouwen.

Each soldier of this detachment was provided with a pair of shoes, two pounds of powder, and rations for three days in a canvas bag suspended at his neck.

The leader of this expedition was Don Osorio d'Ulloa, an officer distinguished for his experience and bravery.
On the night selected for the enterprise, that of the 27th September, the moon was a day old in its fourth quarter, and rose a little before twelve.

It was low water at between four and five in the morning.