Blue Crab season has begun, and fishing boats from North and South Korea are off the west coast of Korea to bring in the valuable crabs. Warships from North and South Korea are out there as well. There have been several minor naval battles, in the crabbing waters, in the past few years. The crab catch is much more valuable to cash starved North Korea than it is to the southerners. So the North Korean crab boats are more likely to cross into South Korean waters to grab more crabs. The South Koreans will tolerate this, up to a point, and then send out gunboats to chase the northern fishermen back into North Korean waters. This often brings out the North Korean navy, to defend their fishing boats from "harassment" by the South Korean navy.