Although it is illegal to operate jetskis in the harbour – as it was at the time of the accident – a number of the water scooters have been seen there in recent months, according to Chief Superintendent Allan Nyring of Copenhagen Police.
Three fines have been issued to people during May and June for using jetskis in the harbour area.
“The accident was fresh in the memory last year, so not much happened then. But now we have already seen one (fine) in May and two in June. So we are concerned about what would happen if we did not close off (the harbour to jetskis),” Nyring said in reference to fences, barriers and signs which were placed at the southern entrance to the harbour earlier this month.
The barriers will remain in place for the duration of the summer season before being re-evaluated.
In January this year, Copenhagen City Court sentenced a 25-year-old man to two years in prison for negligent manslaughter after a jetski he was piloting crashed into a rented boat in the harbour, killing two American students.
The accident occurred on May 6th last year, when the 25-year-old's jetski collided with the boat, which contained seven international students, all of which were United States nationals.
Leah Bell, 18, from Louisiana and 21-year-old Linsey Malia of Massachusetts lost their lives.
The prosecution later appealed the verdict and has asked for a four-year prison sentence to be given.
The appeal hearing will begin at the Østre Landsret high court on Thursday.
Police barriers in the harbour are one of a number of initiatives introduced by law enforcement as a consequence of the tragedy.
Boat patrols in the harbour waters have also been intensified, Nyring said.
“We patrol regularly. People are generally pleased to see the patrols,” he said.
Meanwhile, parliament has approved new rules giving police increase authority to confiscate jetskis and similar craft in instances of dangerous sailing. The rules, which encompass jetskis as well as small speedboats, came into effect on May 15th.