A Hong Kong ferry captain has been jailed for eight years over the death of 39 people in the city's biggest maritime disaster in decades.

A judge handed down the sentence to Lai Sai-ming after his conviction for manslaughter and endangering the safety of others at sea.

The captain of the other boat involved in the 2012 collision, Chow Chi-wai, was given a nine-month sentence. He was cleared of manslaughter but convicted of endangering others at sea.

All of those killed, including eight children, and most of the nearly 100 injured were aboard Chow's boat.

The two captains had blamed each other for the October 1 2012, collision, which came as a shock to the former British colony, renowned for efficient and safe public transport networks.

The verdicts came after a 60-day trial and four days of deliberations.

Lai's commuter ferry was heading from Hong Kong Island to the outlying island of Lamma when the collision occurred. The smaller boat, owned by Hong Kong Electric, was taking employees of the company on a harbour excursion to watch the Chinese National Day fireworks display.

Fleets of ferries form the backbone of the city's transportation network, running frequently to outlying islands, the Chinese mainland and the gambling enclave of Macau.