As monsoonal weather drove most Darwin locals indoors, a motley group of surfers embraced it through air misty with rain and water filled with lurking danger.

Strong winds, good tides and stormy weather produced the kind of surfing conditions, and the kind of surfers, that only emerge a handful of times each year.

"One time I was driving by the coast and this normally flat ocean was just full of swell and full of surfers," recalled Sam Carmody, a lifelong surfer who shelved his board when he moved to Darwin three years ago.

"It was so surreal and I just pulled over and watched everyone for a while and thought they were insane."

Mr Carmody was eventually enticed into the water by the long weekend's unusual swell, and on Sunday afternoon was one of about 30 people paddling through murky water the colour of wet sand.

"It's this strange little miracle moment where Darwin suddenly becomes a very fun surfing location," he said.

Sam Carmody dusted off a surfboard he keeps handy for trips to Indonesia. ( ABC Radio Darwin: Jesse Thompson )

Sam Carmody was recently enticed into Darwin's surf for the first time. ( ABC Radio Darwin: Jesse Thompson )

"It's a very nice vibe," Mr Carmody said of the close-knit surfing community.

In a good year, they will surf in Darwin just 10 or 12 times, many on boards borrowed from mates or stored for trips to Indonesia.

"The first time I went out I was trying to not put my head under the water, which was impossible," Mr Carmody said.

"I just had this idea of this box jellyfish wrapping itself around my face or something."

The Australian literature lecturer, who describes himself as a neurotic surfer, entered the water in a stinger suit while most others sported boardshorts and an optional t-shirt.

The low visibility and rocky shore make for dangerous surfing conditions. ( ABC Radio Darwin: Jesse Thompson )

Monsoonal conditions are responsible for Darwin's rare window of good surf. ( ABC Radio Darwin: Jesse Thompson )

But he said that once he hit the water, his fear of the lurking danger quickly evaporated.

"It's kind of weird how you can put it out of your mind and the fact that there's other guys in the water," Mr Carmody said.

"There's safety in numbers I guess."

Surfers evacuated after three-metre croc sighting

The widely publicised dangers of Darwin's oceans were worsened by the low visibility and strong tides of the weekend's water.

But Mr Carmody said most surfers took it in their stride.

"The locals have all their things that they say, it's kind of their bro science.

"They'll say things like, 'You know, jellies don't like the surf and crocs don't like it — they'll be chilling up the creek somewhere out of the weather'."

The streets were lined with cars as amateur surfers hit the waves. ( ABC Radio Darwin: Jesse Thompson )

The surfing conditions coincided with the first weekend of Surf Life Saving NT's wet season patrol, and many lifeguards spent a busy few days patrolling Darwin's beaches on jetskis and warning swimmers of the risks.

"A lot of them are actually aware of it," Surf Life Saving operations manager Trevor Radburn said.

"You'll go down there and say, 'We've had a few jellyfish', or ,'We've seen a crocodile'.

"The first question is usually, 'How big?' and if it's anything under three metres they say, 'Oh yeah, that's fine'."

Mr Radburn's team found a number of washed-up box jellyfish without tentacles, suggesting the active tentacles had been broken up and scattered throughout the surf.

Bystanders lined the beach to watch surfers battle the waves. ( ABC Radio Darwin: Jesse Thompson )

On Monday afternoon, surfers were evacuated when a three-metre crocodile was seen moving toward the Nightcliff jetty.

"They did find it again for approximately five or so minutes, but it went under again continuing along that way," Surf Life Saving's Sam Edwards from told ABC Radio Darwin's Kate O'Toole.

Gusty winds a kitsesurfer's dream

On Sunday afternoon, three to four-foot-high waves were breaking at about seven second intervals.

As the Bureau of Meteorology issued warnings about the heavy rain, flooding and gusty winds, Darwin's kitesurfing community were making the most of the brief window of opportune weather.

"The worst thing about kitesurfing is if the wind drops, so you always want to have consistent wind," kitesurfer and photographer Charlie Bliss said.

Kitesurfers took advantage of the strong winds to get airborne. ( Supplied: Charlie Bliss )

Regular weekends see about 20 kitesurfers take to the water, but this weekend saw as many as 40.

Mr Bliss admitted Darwin was one of the most challenging places to kitesurf, and not knowing how to navigate the tough conditions could leave a kitesurfer stranded at sea.

"Once you're more competent on the water, you're boosting around at 25 or 30 kilometres per hour," he said.

"Another reason why you feel so safe out there is you can outrun anything."

Darwin's close-knit surfing community only hits the waves a handful of times each year. ( ABC Radio Darwin: Jesse Thompson )

If the wind suddenly drops, kitesurfers may have to initiate self-rescue techniques or paddle back to shore.

"This is the point you'd be letting your kite down and coming back in," Mr Bliss said as a dark and thunderous storm rolled in from the ocean.

Then the piercing rain reached land, drenching spectators and washing all but a game few surfers out of the ocean.