Bay of Plenty Coroner Dr Wallace Bain is calling for changes to maritime law including introducing licences for jet ski operators following the death of a 17-year-old on Lake Okareka.

Kaingaroa teenager Bishop Thompson drowned after being thrown from a jet ski when it collided with another jet ski on the Rotorua lake in January last year.

A 13-year-old girl was injured in a head-on jet ski collision in Maungatapu this year.

His body was later found following an extensive underwater search by police and navy dive teams.

The two drivers of the jet skis were charged under the Maritime Transport Act with operating a ship dangerously.

The charge was later changed to operating a vehicle as to cause unnecessary danger, which both men pleaded guilty.

In a separate incident this year, a 13-year-old girl was injured in Tauranga when the jet ski she was riding collided head-on with another jet ski in Maungatapu on April 17.

She was originally taken to Tauranga Hospital with a fractured arm and abdominal injuries and later transferred to Waikato Hospital.

The girl has since been discharged from hospital.

Dr Bain is recommending all powered recreational vessels or maritime products are registered and issued with an identification number that is highly visible.

In a report into Bishop's death, Wallace says the teen would not have died if the law changes he recommended following the death of 9-year-old Genevieve Lewis in 2009 were put in place.

Genevieve was run over by a boat while waterskiing on Lake Taupo.

Under Maritime New Zealand rules, no person under the age of 15-years-old shall be in charge of, or propel or navigate, a power driven vessel that is capable of a proper speed exceeding 10 knots, unless he or she is under the direct supervision of a person over the age of 15, who is in the immediate reach of controls.

Dr Bain also recommends all operators of powered recreational vessels or maritime products be required to hold a licence when operating a vessel .

Other recommendations on Wallace's report include all candidates for licences be required to know the basic safe boating rules and their legal responsibilities.

He thinks the laws relating to maritime activity should be reformed to incorporate the above recommendations, and provide for a graduated form of penalty similar to the land transport legislation.