The Dutch were surprised by these events but eventually managed to prepare a strong fleet of 75 ships under De Ruyter. However, because delays in his fleet mustering, he was unable to realise his plan of preventing the junction of the English and French fleets to create a force superior to his, so he used three different strategies to meet changing situations in the following two years. Firstly, he aimed to inflict sufficient damage on the English ships to require their lengthy repairs in the congested English dockyards, as in his attack at Solebay. Allied to this, when De Ruyter detected the French fleet'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.