The operator of a high speed jetboat has been ordered to pay $270,000 in fines and reparations after three women broke their backs on sightseeing trips.

The operators of the Paihia-based Excitor III, InterCity Group (NZ), admitted two health and safety charges last month after incidents in January and March last year during trips out to the Hole in the Rock in the Bay of Islands.

In the Auckland District Court on Monday the company copped fines of $120,000 and was ordered by Judge Phil Gittos to pay reparations totalling $150,000 to the three women.

Petula Patey and Amanda Lee suffered spinal injuries after hitting large waves on January 12 last year, while Brisbane health worker Jan Phillips fractured vertebra on March 22 in similar circumstances.

Ms Patey, the most seriously injured of the trio, was awarded $60,000 while the other two women will each receive $45,000.

Both charges were brought by Maritime New Zealand (MNZ)for "failing to take all practicable steps to ensure no action or inaction of any employee at work harmed any other person".

The company was fined $50,000 on the first charge and $70,000 for the second charge.

MNZ investigator Bruce McLaren said company had failed to react to passenger and staff concerns and did not stop its operation to fully investigate the causes of the injuries.

"Despite at least four similar incidents between January and March 2011, including the two serious injury incidents investigated by MNZ, the company did not stop its operation to investigate what might be causing people to get hurt."