Cargo ship drifted off course before grounding in Pentland Firth

Cargo ship Priscilla (IMO 9411745 ) grounded near the Pentland Firth having drifted off course for some time in July 2018 as a result, in  part, of the fact that the officer on watch had been looking at music videos on his mobile phone, the UK Marine Accident Investigation Branch (MAIB) has said in a report.

Early on July 18th 2018 the Netherlands registered, 2009-built 2,281 gt general cargo vessel Priscilla grounded on a charted, rocky reef in the eastern entrance to Pentland Firth, while en route from Klaipeda, Lithuania to Silloth, England.

It was before dawn, but visibility was good and the sea conditions were calm. Priscilla had drifted south of its planned track during its approach to Pentland Firth. When the officer of the watch realised that the vessel was off track and heading into danger, he took insufficient action to avoid grounding.

The vessel was refloated a week later with the aid of tugs, but had suffered significant hull damage and was taken to a dry dock for repairs. There was no pollution or injury.

When approaching Pentland Firth Priscilla had unintentionally been set to the south of its planned track, but this was not noticed because the officer of the watch did not monitor the vessel’s progress for about two hours. Instead, he sat in the bridge chair and watched videos. MAIB said that it was also possible that the officer of the watch at times had fallen asleep.

When the officer of the watch realized that Priscilla was off track, he still had ample time to regain the planned route. Instead, he chose an alternative route that placed the vessel in imminent danger. MAIB said that his happened because he relied solely on radar data and did not refer to navigational information when making what turned out to be a critical decision.

There were no navigational alarms to warn of danger and, although the accident happened at night, no additional lookout had been posted. The bridge navigational watch alarm system was also switched off. Priscilla’s officer of the watch responded to two verbal warnings from shore authorities of the danger ahead. However, the action he took in response to the warnings was not effective. It also indicated that he had not properly understood the situation, had an incorrect “mental model” and did not know what needed to be done to avoid danger.

Since the grounding, the Maritime and Coastguard Agency has taken steps to improve the standards of vessel traffic monitoring in Pentland Firth.

Priscilla’s owner has updated onboard procedures, and a safety recommendation has been made to the owner to take further steps that are intended to improve standards of watchkeeping.

Priscilla’s crew comprised four Dutch and two Filipino nationals;

The master was a 28-year-old Dutch national who had been employed for six years on board Priscilla as the maritime officer then chief officer. He joined Priscilla two weeks prior to the accident on his first contract as master.

The chief officer was also a 28-year-old Dutch national. He had been working on board Priscilla for two years as the maritime officer before being promoted to chief officer. This was his second contract in that role. He was also Priscilla’s navigating officer and safety officer.

The maritime officer was a 23-year-old Dutch national who held a combined deck and engineering qualification with certification issued in February 2018. The maritime officer typically spent two hours a day in the engine room in addition to bridge watchkeeping, and expressed a preference for engineering duties. He had also been experiencing some feelings of anxiety and restlessness caused by the illness of a family member.

Before the maritime officer took over as OOW, Priscilla was in track mode steering, following the planned track in the ECDIS. When the maritime officer took over, he changed from track mode steering to the standalone autopilot. Priscilla was following thereafter the selected heading of 279°. This decision by the OOW to use the standalone autopilot allowed the southerly tidal stream to set Priscilla of track to the south.

Other than a personal preference, MAIB said that it had not been possible to determine exactly why the maritime officer chose the standalone autopilot. There were no onboard procedures or direction from the master to guide the OOW when making his decision.

After switching over the autopilot mode, the OOW then sat in the bridge chair and started watching music videos on his mobile phone. Seated and alone on the bridge in the middle of the night was an environment that created a very high risk of the OOW falling asleep, and it is possible that he did so periodically between about 0230 and 0400. When seated in the bridge chair, the OOW was unable to operate or interact with any of the navigational equipment or cancel the BNWAS. This meant that, whether awake or asleep, and for about two hours, the OOW was unaware of Priscilla’s gradual deviation from the planned track.

When the OOW looked at the port radar display at about 0400, he realized that Priscilla was well to the south of the planned track. The opportunity to alter course to starboard at this point and return directly to the planned route was not taken.

MAIB said that it had not been able to ascertain why this did not happen. However, it was “likely that the OOW was anxious about his perceived mistake of allowing the vessel to drift off track and might not have wanted to alert the master, which could have been the case had an alteration of course been made. This analysis is underpinned by the fact that the OOW did not call the master, which he was obliged to do when he discovered that the vessel had not been kept on track.”

The OOW decided instead to try to steer between two islands that were painting on radar ahead. However, the OOW made no reference to the ECDIS display when making this decision, and the chart overlay function on the radar was not selected. This meant that the decision to pass between the islands was based solely on radar data and not navigational information. As a result, the OOW was unaware that the islands ahead formed part of a shallow, dangerous reef and that his revised plan was unsafe.

At 0430 and with Pentland Skerries about 2nm ahead of the vessel, Shetland CGOC contacted Priscilla by VHF radio. The OOW answered the call, acknowledged the situation and stated that an alteration of course would be made. When the coastguard officer sought confirmation that avoiding action would be taken, the OOW stated “we will see later”.

Having made the radio call, the duty team at Shetland CGOC assumed that Priscilla would alter course away from danger, so no further action was taken by the CGOC watchkeepers.

However, the Orkney VTSO continued to monitor the situation and accurately assessed that Priscilla was still heading into danger. Therefore, the Orkney VTSO intervened directly and initiated another VHF radio call to Priscilla, specifically using the word “warning” to caution Priscilla’s OOW. Only at this point, with the rocks about 0.5nm ahead, did the OOW select the chart information on the port radar display and appreciate the navigational danger.

When issuing the warning, the Orkney VTSO told Priscilla that there was “clear water to the south” five times. With time running out and sensing real danger, it was reasonable for the Orkney VTSO to assume that Priscilla’s OOW would have appreciated that a report of safe water to the south would necessitate a turn to port. However, it was apparent from the OOW’s responses that did not share Orkney VTSO’s mental model of the situation. The OOW said: “I need to go to starboard right?” and “I need to change course to the south?”

MAIB said that the OOW may not even have appreciated that Priscilla was heading in a westerly direction and that heading south would entail turning to port. “The OOW was evidently disorientated and lacked the situational awareness necessary to avoid danger”, MAIB said.

MAIB said that it was of concern that this accident was “characterised by common causal factors identified in previous investigations into groundings of small cargo vessels while on passage”. Those common factors include:

  • the BNWAS being switched off;
  • the absence of a dedicated lookout;
  • ineffective use of the ECDIS.


  1. Priscilla grounded because it drifted to the south of its planned track and the OOW did not correct this deviation when there was ample opportunity to do so.
  2. Instead of returning the vessel to the planned track, the OOW chose an alternative and unsafe route. This decision was based solely on radar information and had not utilised the navigational information available.
  3. Two verbal warnings of the danger ahead were made directly to Priscilla by VHF radio when there was sufficient sea room available to take avoiding action. The response by Priscilla’s OOW to the warning from Shetland CGOC was vague, but went unchallenged by the watchkeeper ashore. Despite repeated warnings from the Orkney VTSO, the actions of Priscilla’s OOW indicated that onboard situational awareness was insufficient to recognize which way to turn the vessel away from danger.
  4. The OOW’s use of a mobile phone for watching music videos when assigned the duty of OOW was a significant distraction; however, there was no guidance or control on board regarding the use of mobile electronic devices.
  5. The decision to reduce to a sole lookout had not been effectively risk assessed taking into account the proximity of navigational hazards and operating at night.
  6. The environment of the bridge at the time of the grounding presented a very significant risk of the OOW falling asleep, and he might have done so periodically.
  7. As the primary means of navigation, Priscilla’s ECDIS was not utilised effectively; key safety features, including safety corridors and warning zones that could have provided warning, were not in use.
  8. Priscilla’s BNWAS was switched off despite the OOW being alone on the bridge at night. The safety protection that the BNWAS could provide was not fully appreciated on board and its use should not have been left to the OOW’s discretion.
  9. Priscilla’s SMS did not provide sufficient guidance for the safe conduct of navigation.

Safety Issues Not Directly Contributing To The Accident That Have Been Addressed Or Resulted In Recommendations

  1. The duty officers at Shetland CGOC were unaware of the presence of Priscilla and the risk of grounding until prompted by the Orkney VTSO. This happened because the coastguard officers were not monitoring their C-Scope equipment and Priscilla had not transmitted a MAREP when approaching the reporting scheme.
  2. The VHF message issued by Shetland CGOC did not follow coastguard procedures, but specifically omitted the key word ‘warning’ used to alert vessels to danger.
  3. It was not appropriate for Priscilla’s master to direct that an unqualified cadet should be left alone on the bridge as OOW and this decision also went unchallenged by the other officers on board.
  4. Hours of work and rest records for the crew of Priscilla suggested that the ABs were keeping night watches as an additional lookout when this was not the case.
  5. Audits of Priscilla did not identify shortcomings in the SMS or weaknesses

Causal factors in this accident include the BNWAS being off, the absence of a dedicated lookout and ineffective use of the ECDIS; all of which had been identified in previous investigations as recurring safety issues in similar accidents.

Safety lessons

  • monitoring the vessel’s progress along the planned passage is a vital component of safe navigation, and the officer of the watch should not become distracted from this responsibility
  • reducing to a sole lookout must be properly assessed; it was not appropriate at night when Priscilla was heading towards Pentland Firth
  • electronic navigation aids should always be set up to aid the officer of the watch by giving warning of danger ahead. The BNWAS should not be left off at sea

Since the grounding, the Maritime and Coastguard Agency has taken steps to improve the standards of vessel traffic monitoring in Pentland Firth.

The owner of Priscilla was recommended to:

Review and improve the safety management system and standards of watchkeeping on board the vessel, specifically ensuring that:

  • All aspects of the passage plan are compliant with IMO guidance.
  • An internal audit regime is in place to effectively monitor safety management.
  • All methods of fixing the vessel’s position are utilised effectively.
  • Hours of rest are recorded accurately for all crew.
  • Crew are prevented from undertaking duties for which they are not
  • qualified.
  • A thorough risk assessment is undertaken prior to making the decision to reduce to a lone watchkeeper.
  • Additionally, Priscilla’s owner has updated onboard procedures; nevertheless, a safety recommendation (2019/118) has been made to the owner of Priscilla to take measures necessary to improve the standards of watchkeeping and safety management on board.

The MAIB holds records of 194 groundings of cargo vessels between 500 gt and 3000 gt that occurred in UK waters between 2008 and 2017. Nine of these groundings, six of which occurred when the vessel was on passage, resulted in a full MAIB investigation and a published report. In five of the six groundings where the vessel was on passage, the BNWAS was switched off and there was no additional lookout on the bridge. Other recurring themes in these accidents include: ineffective use of ECDIS, poor standards of watchkeeping, insufficient passage planning and falsification of hours of work and rest records.

2009-built, Netherlands-flagged, 2,281 gt Priscilla is owned by Beikes JH of Amsterdam, Netherlands. It is managed by Wagenborg Shipping BV of Delfzjil, Netherlands, and ISM managed by Priscilla Scheepvaat CV of the same address.