A tourist has had a very lucky break, spotted drifting on a surfboard off the Australian coast nearly 6 kilometres offshore.

The 37-year-old Japanese man told police he got into trouble while surfing at Bulli Beach, near Wollongong, at about 5:00pm on Thursday.

He got into trouble in a current, tried to paddle back into shore, but the waves were too big, he told police.

He spent the night clinging to his surfboard and it is estimated he spent about 16 hours in the water.

Luckily, the eagle-eyed crew of the 300-metre long container ship MSC Damla spotted the man on top of his rented yellow surfboard.

The rescued tourist was given warm clothes, food and drink after his 16-hour ordeal.

As he drifted alongside the ship, the crew threw him a life buoy, and were able to pull him aboard.

He was given food and drink and warm clothing, and the crew contacted authorities. A boat was sent out to the container ship to retrieve him.

He was taken to Wollongong Hospital where a doctor said he was in surprisingly good health with high spirits, and he was discharged Friday afternoon.

Police said there was no active search conducted for the man, as he was not reported missing.

“This incident is a reminder of the need to let people know your plans before setting out, as well as the importance of knowing local conditions,” a spokesperson from Surf Life Saving NSW said.