Three Fathoms Cove or Kei Ling Ha Hoi (Chinese: 企嶺下海) is a cove in Tai Po District, Hong Kong. It is surrounded by Shap Sze Heung, Kei Ling Ha, Yung Shue O (榕樹澳), Wong Tei Tung and Sham Chung. Most of its east shore constitutes part of the Sai Kung West Country Park.
To the north the cove is connected to Tolo Harbour and the Tolo Channel. The islands of Sam Pui Chau (三杯酒) and Wu Chau (烏洲) are located within the cove.
Coordinates: 22°25′30″N 114°16′42″E / 22.424904°N 114.278326°E