A long running legal battle between rival Queenstown jet boat companies has gone another round in court.
In a three day High Court hearing in Queenstown that ended on Wednesday, the company behind KJet appealed an Environment Court decision in February to grant rival Thunder Jet consent to operate four boats on the lower Shotover River.
The decision broke KJet's monopoly on a stretch of the river from the Kawarau River confluence to Tucker Beach.
This week's hearing before Justice Gerald Nation continued a long running battle between two Queenstown brothers behind the businesses.
Neville and Shaun Kelly have been fighting in court since 2008 over the former's company, Thunder Jet, wanting to operate in competition with the latter's KJet.
KJet has appealed the Environment Court's finding that three of its resource consents had lapsed, alleging several errors in the judgement including a finding that its practice of rotating its consents was not sufficient to maintain them.
James Gardner Hopkins, counsel for Kawarau Jet Services Holdings - trading as KJet - said in his opening submission that the process followed by the court had been ''manifestly and significantly unfair''.
''The effective revocation of a submitter's valuable consents during someone else's consent process is remarkable and without precedent.''
The company wants the consents reinstated, and for Thunder Jet's application to operate on the lower Shotover to be reconsidered.
Pru Steven QC, counsel for respondent Queenstown Water Taxis - trading as Thunder Jet - said in her opening submission that the Environment Court had applied the law correctly and there were ''compelling circumstances'' that counted against the court granting the relief sought by KJet.
Queenstown Lakes District Council is the other respondent to the appeal.
Communications manager Michele Poole said that in relation to one of the consents, KJet had argued that if it had lapsed, then that was the result of a council practice that enabled operators to transfer consents - a practice it had adopted following legal advice in 1995.
Justice Nation reserved his decision.