A 38-year-old man faces a big fine after jumping from a sunset cruise into a fishing lane in Darwin Harbour while allegedly on a date.

The man was charged with entering a commercial fishing lane, and faces a $5,200 fine.

Saltwater crocodiles and deadly box jellyfish are commonly found in the harbour, but the man was apparently unscathed.

• Man, 55, critical after being ‘bashed with scooter’
• Boom times in the big house: our jail obsession
• Search for ‘hit-run’ driver finds culprit close to home

 ABC Darwin presenter Adam Steer was on the cruise and said the man appeared to be intoxicated.

“Suddenly the boat stopped just as the sunset was coming and we had to turn around to rescue said man who had jumped in the drink after looking like he had too much to drink,” Mr Steer said.

“Allegedly he was on a first date.”

After the man had been brought back onto the vessel, he continued causing trouble and was dropped off at the Water Police, said NT Police Superintendent Louise Jorgensen.

“Apparently he had way too much to drink,” Superintendent Louise Jorgensen said.

“A very expensive cruise in the end,” she said.