How did de Ruyter become surrounded at Augusta?

Did de Ruyter know what he was doing at Augusta, and why was his force surrounded?

De Ruyter was using the allies' advantage in viable ships, but Spanish inaction let Duquesne bring his center against the Dutch van from the other side.

De Ruyter was trying to force a battle while the allies had an advantage in viable fighting ships. His van was doing well against its French counterpart. De la Cerda's refusal to close freed Duquesne's center to attack the Dutch van from the other side. The Dutch rear then had to move past the Spanish center to help the isolated van.