 Allied to this, when De Ruyter detected the French fleets's reluctance to become involved in close-quarters fighting, he detached small squadrons in each major sea battle to keep the French out of the main action, concentrating his attack on the English fleet with only slightly inferior numbers.Thirdly, he used the shelter of the shoals, which the larger of the allied ships had to avoid, as a safe haven, keeping the Dutch fleet intact until he could attack the allied fleet at a time and under conditions of his own choosing.In this way, he prevented the English and French fleets from creating the conditions needed to land an invasion force.