05/26/2010 05:12 am ET Updated May 25, 2011

South Korean Ship SUNK: Timeline Of South, North Korea Developments At Sea (VIDEOS)

News of a South Korea ship sinking today off the coast of North Korea has once again boosted tensions between the East Asia neighbors.

The ship, said to have 104 crew on board, began sinking close to North Korea around 10:45 p.m. Friday night, and the exact cause was not immediately clear. Officials later said the ship had sunk.

But news involving South Korean ships or North Korean ships is not uncommon, as the two nations frequently patrol the Sea Of Japan, also known as the East Sea in South Korea and Korea East Seat in North Korea.

Here's a roundup of South Korea and North Korea water-related developments in the news the last few years. Rate each as a major or minor development.