Bright light, loud noise and even a garden hose could be used to try and keep a curious leopard seal away from Auckland's marinas.

Photo: Supplied / Giverny Forbes, Leopardseals.org

The leopard seal named Owha is no stranger to the Waitematā Harbour, having made the waters around Auckland and Northland her home since 2015.

While her frequent appearances at marinas and on pontoons have made her something of a star, boaties aren't so keen on her latest hobby - treating their inflatable dinghies and small boats as chew toys.

But the Department of Conservation has been looking at ways to rein in Owha's potential for troublemaking at one of her favourite haunts, Westhaven Marina.

DOC's acting Auckland mainland operations manager Kat Lane said rangers would work with the marina on a trial to deter Owha in three different ways: using light initially, then noise and as a last resort, water.

But she said they would be treading carefully.

"It's more of a light hosing, so there'll be no use of any fire hoses or anything with full force.

"It's just to try and see if we can move her off the pontoons where she might be causing a problem or where she might be a risk to a member of the public."

Photo: RNZ / Dan Cook

Depending on how the trial at Westhaven Marina goes, Ms Lane said DOC could look at issuing similar permits at other marinas where Owha likes to hang out.

Otago University masters student Giverny Forbes said photos and sightings have allowed researchers to piece together Owha's behaviour and habits.

One is her clear preference for sunbathing on a pontoon, rather than a beach.

"Early 2017 is the last time we saw her haul out on a beach, since then it's been exclusively pontoons - apart from the one time she got stuck up Te Atatu creek at low tide.

"We've managed to document a clear preference change from beaches to pontoons," Ms Forbes said.

That meant, however, that Owha was putting herself in a place where humans were more likely to come into contact with her, Ms Forbes said.

And not everyone's happy with her choice of a sunbathing spot.

Over the last few weeks, Owha's been lurking in the upper reaches of the Waitematā Harbour, around Herald Island and West Harbour marina.

And for fun, she's been popping inflatable dinghies and submerging small boats.

That's left some locals frustrated and facing repair bills of thousands of dollars.

People who see Owha should leave her alone and stay 20 metres away.

Sightings should be reported to 0800 LEOPARD, while DOC wants to hear from anyone who has had property damaged, so they can investigate.