Such battles tended to be decisive, as a wind which was fair to allow the attackers to enter a harbour or anchorage would let neither side out again. As it would normally be more profitable for the attackers to blockade the enemy until they were forced to sortie to accept battle in open water, such attacks were usually forced by lack of time, e.g. by shortage of supplies, the threatened onset of bad weather or the need to coordinate operations with an army on land.