A dive boat operator who left two tourists stranded in the Whitsundays overnight in north Queensland has been ordered to pay nearly $30,000 in fines.

AP Vessel Management, trading as Ozsail, was fined in the Proserpine Industrial Magistrates Court yesterday after pleading guilty earlier this month to failing to ensure the safety of Allyson Dalton and Richard Neely.

The Whitsundays-based company has been fined $25,000 and ordered to pay nearly $5,000 in costs.

No conviction was recorded.

The two certified divers were amongst 20 passengers on the Pacific Star which anchored at Bait Reef, near Hayman Island, on May 23, 2008.

The two tourists were missing in the water for more than 18 hours.

The resulting search and rescue operation is estimated to have cost several hundred thousand dollars and involved seven helicopters, three planes and six boats.