HONG KONG (AFP) - Safety controls on passenger boats in Hong Kong suffer from "systemic failings", an inquiry found on Tuesday after a ferry collision that claimed 39 lives in the city's worst sea disaster in decades.

Pleasure boat Lamma IV was carrying more than 120 people to a fireworks display last October when it collided with the high-speed ferry Sea Smooth and partially sank near Lamma Island.

"In respect of general conditions of maritime safety concerning passenger vessels in Hong Kong... there were and are serious systemic failings in the past and present system of control," the report said.

It said some existing safety regulations were not being properly enforced and that Lamma IV was carrying no child lifejackets on the day of the crash, despite being required to do so by law. Eight children were among those who died in the disaster.

The report found that the marine department had not imposed the child lifejacket standard on the class of vessels in which Lamma IV falls, after resistance from smaller-scale operators who did not want to pay for the safety equipment.

"What is required is systemic change, in particular a change in attitude to responsibility and transparency," it said.

The report also detailed why the Lamma IV sank so quickly and why there were so many casualties. It said the bow of the Sea Smooth penetrated the Lamma IV's main deck cabin, "crushing some of the passengers" and throwing scores of them onto the floor.

The vessel was flooded within minutes with the boat's bow resting on the seabed at an acute angle, it said, causing seats in the upper deck cabin to detach and trap some passengers.

Hong Kong chief executive Leung Chun-ying, who announced the release of the report at a press conference, said it revealed "serious problems" in the marine department.

"We must learn the lesson and spare no efforts in making fundamental improvements and reform to ensure marine safety and restore public confidence," he said.