The Spanish besiegers soon rose to 20,000, a number which was one of the Archduke's preliminary objectives. As the Spanish cannonaded the city, some soldiers tried to wade the moat but this failed and a number drowned. The Count of Bucquoy, commanding forces east of Ostend, had been unable to do the same due over Geule, and began the construction of a dike from the sea up to the city; artillery was placed with which to fire at the boats coming and going from the North. These works were constantly interrupted by the rising sea, evolving under fire from the city and in addition the superiority of the Dutch and English at sea. In addition, the failure of the Spanish closing the north side of Ostend enabled it to receive reinforcements and supplies.