An American tourist was fined yesterday after customs officers discovered cannabis in his cruise ship cabin.Roderick Johnson, 42, pleaded guilty to importing the drug, which he told Magistrates’ Court that he used to help him sleep.“I made a mistake,” Johnson said. “I had no intention of taking it off the ship, I didn’t take it off the ship at all.”According to Crown counsel Robert Welling, on Monday police were alerted by customs officers that a passenger on the Explorer of the Seas had been arrested on suspicion of importing a controlled substance.During a routine search of the ship with a K9 unit, officers discovered a plant-like material in the defendant’s cabin.The material was tested and found to be nine grams of the controlled drug cannabis.Appearing in custody in Magistrates’ Court, Johnson pleaded guilty to the offence and apologised.Senior Magistrate Archibald Warner fined Johnson $1,000 for the offence, ordering him to pay immediately.