Sea-skimming cruise missiles pose the greatest threat to a surface ship in the present-day war scenario. The conventional close-in-weapon-systems (CIWSs) are becoming less reliable against these new challenges requiring extremely fast reaction time. Naval Forces see a high energy laser as a feasible and effective directed energy weapon against sea-skimming antiship cruise missiles because of its ability to deliver destructive energy at the speed of light on to a distant target. The paper compares the technology and capability of deuterium fluoride (DF) and chemical-oxygen-iodine laser (COIL) in effectively performing the role of a shipborne CIWS against sea-skimming missiles. Out of these two lasers, it is argued that DF laser would be more effective as a shipborne weapon for defence against sea-skimming cruise missiles. Besides the high energy laser as the primary (killing) laser, other sub-systems required in the complete weapon system would be: A beacon laser to sense phase distortions in the primary laser, adaptive optics to compensate the atmospheric distortions, beam-directing optics, illuminating lasers, IRST sensors, surveillance and tracking radars, interfacing systems, etc.
