Two UK-based companies, Thorn EMI Electronics and McLennan Marine, have developed a night surveillance system that can enable the coastguards to spot a 20 metre boat at a range of 7.5 kin or a person in water at a distance of 1.5 km. And to top it all, the people being spied at would be totally unaware of the fact that they are being watched, while the images are being recorded on a camcorder.

Called the Marine Electro-optical Surveillance System, it comprises of an infra red searchlight attached to a thermal imager - originally designed to enable soldiers to see in the dark. It works by detecting the heat given off by objects such as humans and engine exhausts.