Family name Sanhai (三海 
, Sanhai 
) , worldwide, is a rare cognomen. The last name Sanhai is habitual in China, where it is a very rare surname, Spain, where it is an extremely rare surname, and India. Not in comparison with a country's population, it is the most numerous in China, India, and the United States. More prevalently, Sanhai is the forename as well as the last name.