A differential evolution based framework is utilized to design an off-line path planner for unmanned aerial vehicles (UAVs) coordinated navigation in known static maritime environments. Considering the problem of having a number of UAVs starting from different known initial locations, the issue is to produce 2-D trajectories, formed by successive way-points, with a desirable velocity distribution along each trajectory, aiming at reaching a predetermined target location, while ensuring collision avoidance either with the environmental obstacles or with the UAVs and satisfying specific route and coordination constraints and objectives. The constraints are imposed in order to maximize the probabilities of UAVs survival and mission accomplishment