Haijian 51 (Chinese: 中国海监 51) is a China Marine Surveillance (CMS) ship in the 5th Marine Surveillance Flotilla of the East China Sea Fleet.

She was christened and commissioned on November 11, 2005 at her 5th Marine Surveillance Flotilla's dock in Shanghai.

The first captain was He Xuming (Chinese: 何旭明).

[1] Haijian 51 was renamed CCG-2151 in July 2013, under a unified, newly established China Coast Guard, integrating the former China Marine Surveillance, China Fishery Authority, General Administration of Customs, Public Security Border Troops.

CCG-2151 has been frequently involved in law enforcement patrol operations in waters around Diaoyu Islands.