No-one was awake on the bridge when the German-owned MV Danio, which set out from Perth, ran aground on the Farne Islands, off the Northumberland coast, despite the Longstone Lighthouse's warning beams flashing across the sea, Newcastle Crown Court heard.
Judge Brian Forster said: "There could have been a major maritime incident."
The Danio set out on the evening of March 15 last year, carrying logs destined for Ghent in Belgium.
At around 3am the following day, the chief officer, who was in charge, fell asleep on a settee on the bridge after putting in eye-drops he needed for an infection. There was no look-out among the six crew.
An alarm which sounded a warning if the bridge was not manned had been switched off because the crew found it irritating, the court heard.
They woke up 90 minutes later with the noise of the vessel running aground.
It hit a reef head-on, then pivoted 180 degrees, getting stuck fast on the outcrop.
No-one on board was injured and there was no leakage from the vessel.
Judge Forster said: "The potential for disaster is obvious. In my judgment there was a lack of effective management, which allowed the situation to come about."
He fined the defendant, Cuxship Management, £60,000 after the firm admitted two breaches of maritime regulations. He also ordered it to pay £12,796 prosecution costs.