The approaches to Tauranga Harbour could soon have new markers for hazardous reefs and shoals - but they won't be cluttering up views.
The markers will be electronic, and appear only on ship navigational systems. The hazard - such as Astrolabe Reef (Otaiti) where the Rena grounded - will appear as a digital information object on the ship's navigation system, electronic charts and radar.
Bay of Plenty Regional Council's maritime operations manager Reuben Fraser said that since the grounding of the Rena in October 2011, the Regional Council had been considering measures to reduce the risk of ships grounding in the region, including virtual aids to navigation.
"The approach to the Port of Tauranga has a number of underwater hazards lying near shipping routes, including Astrolabe Reef, Brewis Shoal, Okapara Reef, Penguin Shoal and Tuhua Reef," he said.
"Western Bay of Plenty harbourmaster Jennifer Roberts is also proposing making a direction requiring all vessels more than 500 gross tonnage or longer than 40 metres to keep more than two nautical miles off land and charted dangers, or any outlying islands in the Bay of Plenty.
These restrictions won't apply to recreational vessels.
"We've identified that a virtual aid to navigation could be a possible solution to marking these five identified hazards, since it would be really difficult to physically mark the reefs."
The virtual marker is transmitted from an Automatic Identification System station, and will alert both the ship and the Regional Council that the vessel is heading towards a charted danger, or enters the no-go zone around each hazard.
"The virtual markers would help the Regional Council with monitoring and enforcement of exclusion zones like these.
"By providing for safer commercial boating we're also helping to keep businesses that rely on the Port operations booming. However regardless of the warning systems that we have in place, if mariners ignore them incidents can still occur," Mr Fraser said.
"It would be beneficial if the system could also collect data on traffic movement in the region. This would give us more information on how the region is used and enable Council to manage shipping traffic more safely."
Tenders close for the virtual marker system on 3 July.