Type 639 has received NATO reporting name Kanhai class,[1][2][3][4] 勘海 in Chinese, meaning Surveying Sea.

In addition to the SWATH hull form, another unique feature of Type 639 oceanographic research ship is the adaptation of integrated electric propulsion system.

The integrated electric propulsion system was the result of work of several CASIC subsidiaries and divisions, including Wuhan Machinery Plant Co. Ltd (武汉船用机械有限责任公司), Henan Diesel Engine Industry Co. Ltd (河南柴油机重工有限责任公司), Shanxi Fenxi Heavy Industry Co. Ltd. (山西汾西重工有限责任公司), Chongqing Huayu Electrical Instrumentation Plant (重庆华渝电气仪表总厂) Archived 2016-03-04 at the Wayback Machine,Beijing Great Wall Electronic Equipment Co. Ltd. (北京长城电子装备有限责任公司) Archived 2014-05-25 at the Wayback Machine, and the final integration of various subsystems of the integrated electric propulsion system is The 712th Institute of CSIC (中国船舶重工集团公司第七一二研究所).

The most obvious visual feature of Type 639 oceanographic surveillance ship is that there is a well in the center to lower acoustic or other scientific equipment.

[5] Type 639/639A series ships in PLAN service are designated by a combination of two Chinese characters followed by three-digit number.