A Royal Navy commander crashed a nuclear-powered submarine into a large rock in the Red Sea after misreading a number one as seven on a navigational chart, a court martial heard today.
Commander Steven Drysdale, who was in charge of HMS Superb, had ordered the vessel to take a shorter route to make sure it reached a rendezvous point in time for an operation. The submarine dived to reach deeper water so that it could travel faster, the hearing at Portsmouth naval base was told.
A pinnacle jutting out from the seabed was marked as being at a depth of 123 metres, but Drysdale misread it as 723. Thinking that the boat would clear the obstruction easily, the submarine was directed towards it and it grounded.
Drysdale, officer of the watch Lieutenant Commander Andrew Cutler and navigation officer Lieutenant Lee Blair all admitted at a previous hearing an offence of neglecting to perform their duty.
Captain Stuart Crozier, prosecuting, told the hearing that the submarine had been suffering from technical problems, causing it to lose speed, at the time of the incident in May 2008. He said there was pressure on Drysdale to ensure the submarine arrived in the Gulf on time for planned operations.
Crozier said Drysdale ordered a new route to be plotted that cut about four miles off the previous plan. He also ordered the submarine to dive deeper to where there was colder water, allowing it to travel faster.
When the new route was charted by the plotting officer, who does not face the court martial, all three defendants failed to spot that the pinnacle marked on the map was only 123 metres deep, the only shallow point in the area.
Crozier said that when the submarine collided with the pinnacle, the vessel was brought to an almost immediate halt. "The submarine collided with the underwater obstacle reducing its speed from 16 knots to three knots in a very short time," he said. "There was a significant amount of damage to the forehead of the submarine, but no casualties."
He said all three of the accused had looked at the chart. "No thorough check was made as to the depths in relation to the decision to take the submarine to this dive depth (250 metres). The new navigational track went directly over the pinnacle which showed 123 metres."
The court martial was told that checking the chart would have been made more difficult because the line of the new route had been drawn directly across the spot where the pinnacle lay on the map, making it difficult to see. The hearing was told that new procedures had since been introduced by the navy so that all depths are rechecked when a new route is charted for a submarine.
Commander Alison Towler, representing Drysdale, told the court that the commanding officer had since been moved to a desk job. She said the service had also stopped Drysdale from taking up the high-profile position of Royal Navy staff officer submarines in Washington DC shortly after the incident.
She said Drysdale, who has served in the navy for 25 years, had inspected the chart but had misread the depth of the pinnacle.
"Cdr Drysdale wishes to express his deep remorse and regret in relation to the incident which has led to this court martial. He fully accepts his responsibility in relation to this matter," she said.
Commander Joe Turner, representing Cutler, said: "He regrets the incident and fully accepts his responsibility. He will have to live with what happened for the rest of his life. He expresses his full remorse."
Commander Stuart Wright, representing Blair, said the navigation officer was "fatigued" at the time of the crash having lost his signal communications officer to illness.
The accident damaged HMS Superb's bow and its sonar equipment, causing it to have difficulty diving. The submarine had to abandon its planned deployment but was able to return to the UK under its own power, the hearing was told.
The submarine, which came into service in 1976, was decommissioned in September 2008 and the MoD has said the accident did not lead to the submarine being taken out of service earlier than planned.
Drysdale pleaded guilty to failing to ensure the safe direction of the submarine, while Cutler pleaded guilty to failing to supervise the plot officer adequately. Blair pleaded guilty to failing to take into account all the dangers in or near the planned movements of HMS Superb.
A British Royal Navy commander was reprimanded on Monday by a court martial, after pleading guilty to "failing to ensure the safe direction" of the submarine HMS ''Superb''. Commander Steven Drysdale was in charge of the nuclear-powered submarine in May 2008, when it struck a rock pinnacle 132 metres below the surface. A navigation chart showed the pinnacle, but Drysdale said that he had misread its depth as 732 metres.

Officer of the Watch Lieutenant-Commander Andrew Cutler and Navigating Officer Lieutenant Lee Blair were also reprimanded for their part in the incident by the court martial, held at the HMS Nelson centre at Portsmouth naval base.


The £32 million submarine was in the Red Sea, heading for the Persian Gulf, and was suffering from technical problems at the time which were slowing it down. The officers decided to dive from 100m to 250m, which would allow them to travel faster and reach their destination on time.

According to prosecutor Captain Stuart Crozier: "The three defendants all looked at the chart and the sub was taken to 250m. No thorough check was made to establish whether this depth was safe from obstacles."

Lieutenant-Commander Cutler then realised that a change to the route could shorten it. “On assessing the chart, Officer of the Watch Cutler saw he could cut the corner of a dog-leg, saving about three to four miles," said Crozier. "He then instructed the plot officer to draw a new line on the chart. However Lieutenant-Commander Cutler did not check the depth around this new track."

"Unfortunately, with the sub now dived to 250m, this new track went directly over a pinnacle which showed only 132m of available depth."

The new route was plotted directly over the pinnacle on the chart, and the court martial was told that this made it harder to spot the error. None of the officers, including Commander Drysdale, realised that they had put the vessel on a collision course.

''HMS Superb'' struck the pinnacle at 10.01 on May 26, suffering damage to its bow and sonar equipment. There were no casualties, but the submarine was forced to abandon its mission and return to the United Kingdom. It was decommissioned in September 2008, though the Ministry of Defence said that this was not due to the accident.

Commander Alison Towler, representing Drysdale, said that he accepted full responsibility and had "deep remorse and regret" over the incident. "He believes that due to the surrounding information he simply misread 132m as 732m" she said. "It was only later that he realised the plot officer had drawn the sub’s new transit straight through the pinnacle, which made it even harder for it to be seen."

Navigating Officer Blair also pleaded guilty to failing to take into account all the dangers in or near the planned movements, and Officer of the Watch Cutler pleaded guilty to failing to supervise the plot officer adequately. All three officers will continue to serve in the Navy, but Drysdale has been moved to a desk job and will not be taking up the position in Washington DC he had planned to.

Captain Philip Warwick, president of the court martial board, told the three: "It was indeed fortunate that no one was hurt and we note that the submarine could not complete its deployment in full. The failings were unacceptable and we take an extremely dim view of them."

The Royal Navy has since brought in new procedures on submarines to prevent a repeat of the incident, requiring that all depths are rechecked when plotting a new route.