Crooked Harbour or Kat O Hoi () is a harbour at the northeast of New Territories, Hong Kong. The harbour is connected to Double Haven and the bigger sea of Mirs Bay. Crooked Island, also known as Kat O, and several islands, including Ap Chau, form the harbour with the mainland New Territories. Islands Islands of Crooked Harbour include: Ap Chau Ap Chau Mei Pak Tun Pai Ap Chau Pak Tun Pai Ap Lo Chun Ap Tan Pai Ap Tau Pai Cheung Shek Tsui Fun Chau Kat O Lo Chi Pai Sai Ap Chau Siu Nim Chau Tai Nim Chau Ecology Wave-cut "benches" of 6 to 10 meters wide form along the sediment layers at Crooked Harbor and Ping Chau, which are uncommon elsewhere in Hong Kong's coastline. Eelgrasses discovered at Lai Chi Wo in 1977 were granted protection by the Agricultural and Fisheries Department of the Hong Kong government. Periclimenes demani, a small species of shrimp, resides in this grass. Historical event On 8 June 1857, a British naval frigate encountered pirates at Crooked Harbor, 70 men leapt overboard and were massacred on land. References Ports and harbours of Hong Kong North District, Hong Kong