A drug user drove his multi-purpose vehicle (MPV) into the waters off Sentosa Cove in 2017 and had to be rescued.
Lim Jin Ping, 37, admitted that he had smoked amphetamine every day in the week before the incident on Aug 25 that year.
Yesterday, he was sentenced to 11 months and four weeks in jail and also disqualified from driving all classes of vehicles for two years.
The former private-hire car driver pleaded guilty in November last year to two mischief charges, as well as one count each of assault and drug consumption.
An Institute of Mental Health (IMH) report, dated Sept 14, 2017, stated that he was intoxicated with amphetamines, leading to psychotic symptoms such as auditory hallucinations and paranoid delusions.
The symptoms ceased when he was in remand at IMH.
The court heard that he was admitted to IMH in 2012 and 2015 for drug-induced psychosis after consuming amphetamines.
At about 2pm on Aug 25, 2017, Lim drove to the Sentosa Gateway entrance and smashed through a gantry barrier, causing damage which came to $1,605.
He then drove against the flow of traffic at a roundabout towards Tanjong Beach Walk. About six minutes later, he drove through another barrier behind Tanjong Beach Club.
Sentosa ranger Imran Kamarudin, 31, saw the MPV heading towards him. Before he could get out of the way, the car hit the right side of his body, causing him to roll off the bonnet and onto the ground.
Mr Imran and a colleague pursued the car on their bikes as it headed towards Tanjong Gate.
Lim rammed into the closed gate, causing $2,190.59 worth of damage, and drove against the flow of traffic in Cove Drive.
When he reached the entrance of W Singapore Sentosa Cove hotel, he made a right turn, driving towards the marina, after which the vehicle plunged into the water.
Deputy Public Prosecutor Yang Ziliang told the court that ship captain David Roberts, 36, who is trained in lifesaving, dived into the sea on seeing what happened.
"David reached through the open driver's window and unbuckled the seat belt of the accused... David used a stone to break the back window of the vehicle and pulled the accused out of the submerged vehicle," the DPP added.
An ambulance took Lim to Singapore General Hospital, where his urine sample showed traces of amphetamine and methamphetamine.
The court was told that Mr Imran had to seek medical attention for injuries, including bruises to the right side of his body and knee. He was granted medical leave until Aug 31, 2017.