View source for MHC - Coastal Minehunter

Coastal Minehunters are ships that are designed to find, classify, and destroy moored and bottom mines from vital waterways. Coastal minehunters are generally smaller and with lower sea-keeping and endurance than oceangoing minehunters. They are usually tasked with keeping fixed high-value choke points clear of mines, such as the approaches to military ports and harbours. In a Cold War context it was especially important to protect those ports used by a nation's ballistic missile submarines.

http://en.wikipedia.org/wiki/Coastal_minehunter