With increasing public awareness and concern for the environment, recent fuel spills have shown that the cost to a company can far outweigh than the downtime and cleanup expenses. As more stringent statutory regulations are introduced in the developed countries, cost effective and reliable leak detection systems are in demand. Pipelines are generally the most economical way of transporting large quantities of oil over land, compared to the cost of shipping by railroad. Although pipelines are also built under the sea, the process is economically and technically demanding, which means that the majority of trans-oceanic oil is transported by oil tanker ships.