Drug-fuelled Derek King wrestled a £250 Dolce and Gabbana watch from the wrist of victim Dominic Boag on board a bus.

Greenock Sheriff Court heard how Mr Boag, 22 — who works as a psychic for a national newspaper — was left ‘shaken and upset’ by the incident.

King boarded the bus in Port Glasgow with a drug-impaired pal and declared ‘I’m Derek King’ before targeting Mr Boag.

Prosecutor Kevin Doherty said: “Both were under the influence of something or another.

“The other male engaged Dominic Boag in conversation and noticed that he was wearing a silver Dolce and Gabanna watch.

“Mr Boag told them that it was just a watch. Derek King grabbed his arm and forcibly removed the watch from Mr Boag’s wrist.

He left the bus with his companion and was seen to run away. Mr Boag was upset and shaken by what had happened to him.” The cruel robbery occurred at around 1.30pm on 5 November last year after King, 21, boarded the service to Greenock town centre at Port Glasgow’s Tiree Avenue.

Fiscal depute Mr Doherty told how Mr Boag tried to stop him by shouting out: “He’s stolen my watch.” The court heard how he contacted his partner before reporting the robbery at Greenock police office.

Mr Doherty said: “Mr Boag has certain health difficulties.

“He has Leber’s disease and is registered blind but still has some peripheral vision.” The court was told how Mr Boag’s mother later encountered King by chance in the Port’s Princes Street and noticed that he was wearing her son’s watch.

Mr Doherty said: “She challenged him about the incident.

“Derek King said, ‘Aye, it was probably me’.

“He showed her the watch that he was wearing. King was asked to remove the watch by Mrs Boag and he did so and handed it back.

“Its value is £250.” Mr Doherty added: “CCTV from the bus showed Derek King and Dominic Boag in a struggle.” Mr Boag’s father — who died in 2006 at the age of just 41 — was a former Morton captain.

Defence lawyer Gerry Keenan said: “It was quite apparent that Mr King and his associate were significantly impaired because of the use of controlled drugs. Despite his lack of recollection, he accepts full responsibility.” Solicitor Mr Keenan added: “Mr King has struggled from a very young age with addiction to controlled drugs.” Smirking King — who was remanded in custody four months ago on the robbery indictment — had earlier swaggered into the dock in handcuffs, stating: ‘Whit’s happenin’?’.

He had also been charged with robbing a man of a bracelet onboard a bus six days prior to his attack on Mr Boag, but prosecutors accepted his not guilty plea to that.

Sheriff Ian Fleming jailed King for a 96-day unexpired portion of a previous sentence for assault and added a further seven months in prison for the robbery.

King smiled, turned to his relatives in the public gallery as he was being led away, and declared: “Result!”