‘Stop Work’ Authority Saves Lives

Welcome to this edition of FEEDBACK.

Once again, we feature reports filled with invaluable safety insights for all sectors of the maritime industry, and we are very grateful to those who have shared their concerns and experiences with us. You really are making shipping safer for all! during passenger excursions which should not have been allowed to proceed, liferafts which were neither properly maintained nor properly secured, a close quarters situation which was the result of blind adherence to an engine performance test, and poorly designed pilot ladders which were probably purchased because they were cheap. These reports reinforce the need for the industry to adopt a culture that empowers crew members to reject patently unsafe equipment and to constructively challenge hazardous procedures. The best employers already encourage such interventions.

The danger of enclosed and confined spaces is another emerging theme. We discuss a shipyard worker who suffered from exposure to carbon monoxide because he was working unsupervised and unsupported, and an officer who acted on impulse to try to rescue a crew member who collapsed in a tank due to the inert atmosphere. It is human nature to try to rescue a shipmate who collapses in an enclosed space, but all too often people rush in without the appropriate safety gear and make the situation worse. Always stop and think after raising the alarm, and never enter such a space without all the necessary equipment and support.

We also feature reports where final checks were not completed after maintenance work, resulting in an open manhole and an unsecured vent pipe. Remember that a job is not complete until it’s been checked and signed off by the appropriate officer.

This edition also features our very first report involving marine autonomous surface ships, or unmanned vessels, one of which seemed to deviate from the requirements of the Collision Regulations. Bridge watchkeepers should be aware that such vessels must comply with the Collision Regulations, and should be capable of being contacted by VHF radio. Keep a safe distance and avoid the temptation to go for a closer look, and please let us know if you have a similar experience.

Reports

M2297 - Unfinished maintenance creates hazard

Initial Report

During routine safety rounds in the engine room, the crew found that the vent pipe for the main engine lube oil settling tank had not been properly resecured back into position after it had been removed during maintenance. This oversight posed a significant risk, as the pipe could fall from the tank top while the ship was underway.

CHIRP Comment

Although the crew deserves praise for their diligent safety checks and quick response in reporting the issue to the chief engineer—especially given the difficult location of the settling tank vent pipe—leaving the job unfinished is unacceptable, given the tank’s importance.

If the pipe were to fall to a lower level in the engine room, it could result in fatal injuries or serious damage to nearby machinery. Additionally, the unsecured vent pipe leaves the settling tank exposed to potential contamination.

Work like this requires a detailed toolbox talk and a proper risk assessment. No task should be considered finished until it has been inspected and signed off by a supervisor, and this should be clearly stated in the toolbox talk.

This report raises several questions: were there enough people available to complete the task properly? Did the team get distracted by another task- if so, what procedures were in place to ensure that it wouldn’t be forgotten? Were supervision levels adequate?

Situational Awareness- The crew working on the job appeared unaware of the potential consequences of leaving the vent pipe unsecured. If the hazards had been properly identified during the risk assessment and toolbox talk, would the pipe have still been left unsecured?

 Teamwork- The crew should have questioned the security of the pipe and taken steps to re-secure it. If you were part of this job, would you discuss the necessary steps with your team? Does your company have a strong safety culture that fosters teamwork and a shared understanding of safety?

 Alerting- The crew member who reported the hazard to the chief engineer deserves recognition for their quick action in raising the issue.

 Procedures- No task should be considered complete until it has been inspected and signed off by a senior engineer.

M2307 - Life raft maintenance was ignored

Initial Report

Upon boarding a large superyacht which had been relocated between continents, the reporter prioritised safety checks. They discovered both life rafts needed to be correctly rigged and were mislabelled, with unreadable hydrostatic release units (HRUs). One life raft had a painter line incorrectly secured to the cage instead of the HRU, while the other life raft was not secured to any fixture.

Seeking immediate action, the reporter sent the rafts to a nearby manufacturer for annual servicing. The manufacturer identified serious discrepancies, including oversized strapping that could potentially hinder the life raft canister opening.

During an inflation test witnessed by the yacht manager and deck crew, both rafts exhibited alarming issues: water infiltration, mould, corrosion of some fittings, and disconnected gas cylinder firing pins. Corroded high-pressure gas lines further compromised safety, leading to one line’s failure during testing, emitting CO2 into the workshop.

These findings underscored the rafts’ unfit condition, with expired flares and unprotected safety equipment, which would have posed grave risks in an emergency.

The new management has carried out a rigorous inspection regime to ensure that the vessel’s safety has been brought to a state of operational readiness.

CHIRP Comment

Life rafts are essential life-saving appliances and must be properly maintained. The service company responsible for this maintenance should always be reputable and approved. Unfortunately, no maintenance had been conducted, and inspections—both internal and by the flag and port state—had failed to identify the problems. Additionally, crew members were unaware of the condition of the life rafts, their hydrostatic release units, or their securing points. This highlights a serious lack of safety culture within the company, leaving the crew with equipment that would not function in an emergency.

It is excellent practice, as the reporter demonstrated, to witness the inflation of the life rafts during servicing by the appointed company. Doing so ensures that maintenance standards are upheld and reassures the crew that the life rafts will function correctly when needed. The reporter deserves commendation for prioritizing safety upon joining the vessel. The flag state were altered to the poor quality inspections.

Capability: The failure to recognize an unsafe situation with the life rafts highlights a lack of knowledge and experience among the crew at all levels. During safety inspections on your vessel, do you participate in the inspection process? During safety drills, are life-saving appliances (LSA) explained to you? Do you know the correct method for securing the life raft hydrostatic release units?

 Culture: Do you feel that the company employing you as crew on board your vessel genuinely cares about your safety?

 Alerting: The reporter has gone the extra mile to highlight how poor the safety conditions on the vessel are. These actions have led to a positive change in safety practices.

M2305 - Close quarters situation

Initial Report

The skipper of a recreational sailing vessel was the stand-on vessel in an encounter in calm sea and bright daylight with a radar reflector and AIS in operation. The skipper reported:

“A large container vessel passed us very close astern… within 50m. I maintained my course and speed as a stand-on vessel. The ship claimed that the engineers had to perform engine performance tests and, therefore, had to keep their course and speed.”

The skipper sent CHIRP a video of the conversation and screenshots, which confirmed their report.

CHIRP Comment

Engine performance testing is a routine operation carried out periodically by most merchant ships. It is done to identify problems and prevent major failures, improve efficiency, optimise performance, assess quality and ensure compliance with environmental regulations. It is part of the SMS and PMS.

Such testing is carried out ideally when conditions are good and external factors such as wind, sea state, and current are as low as possible to obtain the best results. Maintaining course and speed ensures that the load on the engine is stable; however early and gentle alterations of course of one or two degrees at a time using minimum rudder movements can avoid a close-quarters situation developing without jeopardizing the engine performance test. In any event, adherence to ColRegs is paramount and the trial should, if necessary, be abandoned and rescheduled. Did the container vessel OOW lack the confidence to abandon the trial, or did they feel that they were not empowered to do so? CHIRP posed these and other questions to the vessel’s management company, who were extremely helpful in investigating this incident.

Although the sailing vessel was the vessel not to be impeded and maintained its course and speed (ColRegs rule 17a ii) it was evident that a risk of collision existed, and it was thus obliged (ColRegs rule 8f(iii)) to take action under rule 17b to avoid collision. Large, high-sided vessels have a blind sector at very close range and the yacht was probably not visible from the larger vessel’s bridge at only 50m.

Situational Awareness– Whilst engine performance testing is important, the paramount requirement is to adhere to the ColRegs. Remember that large vessels have a ‘blind sector’ that often extends a long way from the bow.

Culture- The company should ask whether its officers have the necessary confidence to challenge instruction/orders even when there is a known danger.

M2300 - Open Manhole Cover Creates Hazard

Initial Report

During coal cargo discharge operations, the duty officer noticed that the manhole cover on the lower stool between cargo holds 2 and 3 had been left open without any warning signs.

It was later found that work had been interrupted, and the access to the stool was left open before loading began. In a toolbox meeting held afterwards, it was clarified that accessing the stool required an enclosed space entry permit, along with a proper risk assessment. Due to the nature of the cargo, the stool structure could potentially contain dangerous levels of methane gas.

CHIRP Comment

Entry into enclosed spaces requires a permit to work to be opened, which should be signed off and closed once the work is complete. This cannot have been properly done on the previous occasion that it was opened and is a serious violation of the enclosed space entry requirements, indicating significant deficiencies in the ship’s safety procedures.

While uncommon, these incidents emphasize the critical need for thorough inspections before loading operations begin. Independent inspectors normally check the holds, but if the new cargo is the same as the previous one then this inspection might have been omitted, or conducted from the deck, leaving the open manhole unnoticed.

The potential risks of these oversights are severe, particularly with cargo entering the stool, which would make retrieval difficult, especially as methane gas could accumulate in the area, creating a fire or explosion hazard.

Capability—The crew lacked the necessary capability to properly carry out basic enclosed space entry procedures. Ensuring that the cargo hold is secure and ready for the next cargo is vital for maintaining safety on board.

Communications- There seems to be a breakdown in communication on the vessel, as evidenced by the failure to secure the manhole lid. This crucial piece of equipment was overlooked, indicating a weak reporting culture that needs to be addressed.

M2292 - Confined space carbon monoxide poisoning

Initial Report

A shipyard has been fined after a welder suffered carbon monoxide (CO) poisoning while working in a confined space on a ship in drydock. The welder continued cutting metal for 40 minutes, unaware that his gas monitor had been sounding an alarm.

According to the incident report, the alarm went off just two minutes after the worker began arc gouging, a welding process that uses a carbon electrode, power, and compressed air to cut metal. This alarm should have prompted an immediate evacuation, but the welder didn’t hear it and kept working until he started feeling sick and left the space on his own.

The report also revealed that the welder should have been wearing a full-face respirator with its own air supply. However, the respirator was broken, so he used a half-face respirator, which did not protect him from CO.

Additionally, the person assigned to monitor the welder had not been properly trained and was not at the entrance of the confined space for at least 40 minutes. When the welder finally exited, another worker noticed his condition and raised the alarm. Paramedics took the welder to the hospital, and he made a full recovery.

CHIRP Comment

This report highlights several serious safety violations that could have been fatal, especially in the challenging environment of a shipyard or during vessel maintenance. It underlines the importance of clear responsibilities between the ship’s crew and the shipyard’s contractors.

Dry docks are among the most dangerous workplaces for seafarers and shore workers. With so many tasks happening simultaneously and a shortage of qualified personnel, there is often pressure to finish work quickly. Many shipyards rely heavily on contractors and temporary workers. This places an obligation on shipyard management to ensure these contractors have the skills and knowledge to perform their jobs safely, and to oversee them to ensure that they adhere to documented safe systems of work.

In general, the ship’s master is responsible for the safety of the ship, its crew, and anyone else on board, including shipyard workers and contractors. The master also has to ensure that all work areas are safe, typically through a Permit to Work system. Meanwhile, the shipyard must ensure that its workers are properly trained and capable of doing the work safely, with risk assessments and inspections in place to maintain high standards. The provision of welding sentries and other safety personnel is usually agreed upon in formal meetings between the ship and the shipyard unless specified in the contract. CHIRP recommends that company SMS documents are reviewed and updated on drydock safety management to ensure they include all identifiable risks to the crew and the shipyard workers.

In this incident, the space was a confined space rather than an ‘enclosed space’ (see definitions below), and not properly risk-assessed by the shipyard for hazards arising from the intended work. The company failed to monitor the space while the worker was inside, failed to provide a trained welding sentry, and failed to supply the correct protective equipment for the welder.

Enclosed Space- Defined as a space with limited openings for entry or exit, inadequate ventilation, and not designed for regular occupancy.

Confined space- Defined as a space that is large enough for an employee to enter and work in, with limited or restricted entry and exit, and not designed for continuous occupancy.

Confined space permits require clear communication between workers inside and a safety person outside, usually through radios or visual signals. However, these methods were not in place during this incident, worsening the situation.

Culture- Shipyards must ensure that the proper equipment is available for safe use and provide appropriate training programs, especially for drydock safety. Given that drydock work is one of the most dangerous environments, the lack of training and experienced personnel was a serious oversight.

 Capability- While shipyards do have safety teams, they are often overworked and stretched thin. This means the ship’s crew needs to be extra vigilant about enforcing safety measures that are usually routine on board, particularly in a drydock or repair dock setting. Both the welder and the standby crew lacked adequate training, and safety protocols require that only experienced and trained personnel be assigned to such tasks. Furthermore, the task was conducted without the necessary personal protective equipment (PPE), highlighting a lack of operational knowledge. The use of an incorrect half-face respirator further emphasises this gap.

 Pressure- Drydocks often have a line of ships waiting for access, creating intense pressure to complete work quickly. Effective management, with careful daily planning, is essential to ensure that all tasks are properly assessed for safety risks. Does your company have tools to ensure that work is being carried out safely under such pressures?

 Communications- There was a critical breakdown in communication between the welder and the standby person who was supposed to be monitoring both the work and the atmosphere in the confined space. This lack of communication further endangered the worker.

 Teamwork- Teamwork in this situation was inadequate. The standby crew member abandoned their position for over 40 minutes, showing a clear lack of awareness of the dangers involved. Proper teamwork is crucial in ensuring safety in high-risk environments like drydocks.

M2308 - Unsafe Pilot ladders

Initial Report

The reporter stated that a pilot ladder had to be condemned as it was unsafe for use. It had very loose steps, which is typical of a certain manufacturer whose ladders seem to have a serious design flaw. The matter has been raised to the port authority.

 

CHIRP Comment

There is a notable issue with the manufacture and design of pilot ladders, particularly regarding the stability of the steps. A common problem arises with the clamping mechanism used to secure the chocks, if it is not robust enough to ensure that the ladder steps remain horizontal throughout the ladder’s working life.

Some pilot ladders have good clamping and are constructed in accordance to ISO799, and some manufacturers have clamps that come loose at 300k force (where 880k is mandatory as per ISO799).

Regarding the steps, IMO A.1045 states in 2.1.2.7: they should be secured in such a manner that each will remain horizontal. If rope is used to secure the steps to keep them horizontal the correct type of rope to assemble a ladder is three-ply tarred marlin of minimum breaking strength of 800N (ISO799-1:2019 rule 4.7)

On a related note, using shackles to secure the ladder damages clamping mechanisms and makes the steps become loose. Shackles must not be used. Pilot ladders shall only be secured at intermediate lengths by a device designed by the manufacturer for that purpose, or a rolling hitch. No other method is acceptable.

CHIRP wishes to remind readers that pilot transfers are high-risk operations. It is crucial for crew members to maintain heightened safety awareness to ensure that the transfer from the pilot boat to the bridge is conducted as safely as possible.

To address this safety concern, CHIRP recommends developing a standardized securing arrangement for pilot ladders, approved by pilots, to ensure step stability. It encourages collaboration among manufacturers to create a common design that improves ladder safety.

Additionally, it is essential for companies to assess their crews’ understanding of pilot transfer arrangements. These assessments can be conducted during internal audits, safety inspections, and visits to the vessel by the Designated Person Ashore (DPA). Regular evaluations will help ensure crews are adequately trained and that safety protocols are consistently followed

Design- Clearly, there are flaws in the design. This is borne out by the number of times that pilots are seeing the same issue. How do you assess the quality of the pilot ladder when one is procured by the company? Do you have any input in the procurement process?

 Capability- Pilot Transfer Arrangement (PTA) knowledge and safety can easily be assessed by management. Does your company have a process for ensuring that the crew have the necessary knowledge? Does your company carry out training for PTA?

M2291 - Fatal tank inspection

Initial Report

During a nitrogen inerting operation on a ship, nitrogen was being pumped into the tanks to displace oxygen, which helps preserve the cargo and prevents oxidisation. Before the process began, an able seaman (AB) conducted a final inspection to ensure the tank was clean and ready. However, after the inspection, the ship’s captain noticed the AB had not reported back as expected and sent the chief officer to check on him.

When the chief officer arrived, he found the AB unconscious on the lower platform inside the tank and immediately raised the alarm. The captain rushed to the scene, only to find the chief officer also unconscious on the upper platform. A rescue team equipped with breathing apparatus entered the tank and retrieved both men. Sadly, the First Officer could not be revived, while the AB was severely injured and required hospitalization.

The investigation revealed that a faulty valve had caused nitrogen to leak from an adjacent tank, displacing oxygen and creating a deadly environment. Although the crew was aware of safety protocols for confined space entry, they had not been followed. Critical steps such as conducting a risk analysis, performing gas measurements, and issuing an enclosed space entry permit were not carried out before the AB’s inspection. Furthermore, although both the AB and chief officer were wearing protective gear, they did not carry personal gas analysers.

This incident highlights serious safety failures that led to the tragedy and underscores the need for strict adherence to safety protocols, proper risk assessments, and the use of appropriate equipment when entering enclosed spaces.

CHIRP Comment

Tank inspections are typically conducted by an officer. In this case, nitrogen likely leaked from an adjacent tank through interconnected pipes, which can happen even with double-valve isolation.  CHIRP strongly recommends that vessel Safety Management Systems (SMS) direct that, once inerting has started, all cargo spaces should be considered inert (ie dangerous), even those previously ‘certified safe’, and entry is prohibited. This episode clearly shows that hazards can, and do, arise through unforeseen leaks during inerting that render safe spaces lethal.

The incident sussgests a poor onboard safety culture. The management failed to adequately resource and train the crew or enforce safety protocols. The fact that no one questioned the decision to enter the tank without necessary safety controls suggests a lack of investment in both crew training and a robust safety culture.

These controls would have included critical safety steps, such as wearing a personal gas analyser to detect hazardous gases. The lack of challenge suggests that deviations from safety protocols were accepted practice on board.

Culture – The organisation lacks a strong safety culture. Would you enter a tank if directed to do so without a proper enclosed-space entry permit? The company urgently needs to reassess its safety management system, involving both the flag state, class authorities, and its insurers, to implement substantial improvements in their operational procedures.

 Situational Awareness- The crew did not fully understand the operational environment, and there was no intervention from other crew members to prevent the unauthorized entry. This lack of awareness tragically resulted in the loss of a crew member’s life.

 Overconfidence- Confidence should never be a factor in enclosed-space entry. Such environments are inherently unnatural and carry a heightened risk of incidents occurring due to the numerous potential hazards within a tank. Proper precautions must always be taken, regardless of prior experience or perceived familiarity with the task.

M2261 - Critical safety failures and crew fatigue on cruise ship during passenger excursions

Initial Report

A crew member on an expeditionary cruise vessel reported serious safety concerns following a recent passenger excursion.

The vessel planned to land passengers at a remote location known for its impressive wildlife. There was a considerable onshore swell, so the vessel anchored a mile offshore. The captain assessed that the distance to shore, the sea state and the surf conditions on the beach exceeded the safe operating limits for the vessel’s own inflatable passenger launches, and a local, larger, ferry was commissioned to move passengers ashore.  Unfortunately, however, the ferry ran aground on its way out of harbour. To avoid cancelling the trip, and without consulting with the captain, the expedition leaders directed that the passenger launches be used, and nominated several of the crew members as helmsmen, even though not all of them were qualified to do so.

Our reporter was one of several people who expressed concerns to the expedition leaders, pointing out that this went against the captain’s earlier orders, and the weather had further deteriorated. These concerns were over-ruled.

The launch crews then worked from 8am to 7pm without breaks or meals, in tropical heat and high humidity. The considerable sea state, surf, and lengthy transits were uncomfortable for the passengers and highly stressful for the crews, who were aware that they were operating in unsafe conditions, which were further exacerbated by the lack of reliable communication equipment. Several safety incidents occurred, including a man overboard incident, and passengers left on a beach near wild animals.

Following the day’s operations, one crew member experienced severe psychological and mental stress, which the onboard doctor later assessed. After submitting an official report to the captain detailing these safety concerns, the crew member was summoned to a meeting with the cruise director and was asked to disembark at the next port of call.

CHIRP Comment

This report raises important safety concerns, particularly for expedition cruise ships that emphasize excursions. The pressure to meet passenger expectations can lead expedition leaders to prioritize the delivery of excursions at all costs. In this case, delays caused by a grounded ferry likely created additional time pressure, which may have pushed the leaders to use the ship’s launches without consulting the captain. Without deck experience, they may not have fully understood the safety risks, especially if the crew operating the launches were not properly trained. Ignoring the captain’s earlier orders also undermined the captain’s authority, which was further weakened when the captain failed to reassert control after discovering the launches were in use. CHIRP has ascertained that there is no industry SOP for the transfer of passengers from cruise liners other than individual company Safety Management System (SMS) guidelines and procedures.

A ship’s launch has both design limits (such as maximum passenger capacity or sea conditions) and operational limits, which take into account passenger mobility, safety, and comfort. To help make better decisions on board, companies are encouraged to define these operational limits in their SMS. This should include not just weather and sea conditions, but also passenger mobility requirements. Some companies use a simple ‘step test’ to assess if passengers can safely board or disembark.

Using the ship’s launches with unqualified personnel and without proper communication equipment should have been an obvious safety risk and a clear violation of the company’s SMS. However, the expedition leaders overlooked these concerns in their focus on satisfying their passengers cruise experience. Several passengers reported safety concerns to CHIRP.

The crew’s high workload, along with insufficient rest and food, further compromised safety. The 11-hour work shifts left tender operators fatigued, leading to risks that were not minimized to acceptable levels (As Low As Reasonably Practicable, or ALARP).

Additionally, the cruise director did not properly care for a crew member suffering from work-related stress, which raises concerns about ethical working practices.

CHIRP brought these issues to the attention of the company, which dismissed them, so the matter has been escalated to the vessel’s flag state and classification society, both of which are now investigating.

Culture- The company was dismissive when contacted by CHIRP, suggesting its safety culture is lacking. The practical consequences were a series of safety violations including the captain’s orders being ignored and the crew’s concerns rejected. Despite objective evidence with two serious incidents, risky behaviour was allowed to continue and there was no intervention by the master.

Fit for purpose– Neither the launches nor the communication equipment were suitable for the task.

Capability— Some crew members were not qualified to operate the launches, and their capability was further eroded by fatigue in the difficult weather conditions.

 Communication– There was a breakdown of communication between the captain, expedition leaders and launch crews.

Teamwork- Members of the team were focused on different goals and there was no shared understanding of the risks nor the importance of safety. Collective challenge was ignored, and the crew did not have ‘stop work’ authority despite the hazards.

Local practices– Local practices are clearly stressful and should be reviewed by the company’s HR team at the earliest opportunity.

M2304 - Collision Regulations and autonomous maritime vessels

Initial Report

Our reporter recounts an encounter between their large vessel in the North Atlantic and two small autonomous surface vessels, also known as Maritime Autonomous Surface Ships (MASS). Although both vessels were detected on AIS and radar from 7 nautical miles away, visual detection was difficult, even in mild sea conditions.

The first vessel was directly ahead of the ship and the closest point of approach (CPA) was approximately 0.5 nautical miles.

About 45 minutes later, a second, slightly smaller uncrewed vessel was encountered. It was initially assessed to be drifting, with a CPA of 0.2 nautical miles on the starboard side, and the ship altered course to port to increase the CPA to 0.4 to 0.5 nautical miles. However, as the ship approached, the uncrewed vessel increased speed to about 5 knots and started crossing the ship’s bow at close range requiring an immediate alteration of course to result in passing at a safe distance.

CHIRP Comment

There are an increasing number of uncrewed vessels operating at sea, and the IMO is developing a MASS Code for adoption as early as 2025. In the interim, existing regulations such as SOLAS and the Collison Regulations apply, and vessels must have a designated human ‘master’ regardless of the level of autonomy (see table). This person, if not on board, will work from a remote location and remains obliged to maintain a proper lookout by all available means (ColReg rule 5). Presently this includes transmitting its location on AIS and monitoring VHF – even uncrewed vessels should respond to radio calls!

 

Table 1: The IMO’s 4 degrees of autonomy

Degree Definition
1 Some processes automated but there are seafarers on board
2 Remotely controlled ship with seafarers on board
3 Remotely controlled ship without seafarers on board
4 Fully autonomous ship

 

Vessels encountering autonomous vessels should treat them as they would any other vessel and apply the ColRegs accordingly. This includes passing at a safe distance, and not making the mistake of approaching closer because of their small size.

Mariners encountering uncrewed surface vessels (USVs) during commercial and recreational navigation are encouraged to identify and record the AIS information and report any deviations from the Colregs to CHIRP Maritime (reports@chirp.co.uk)  Such reports will contribute valuable insights into the operational challenges and safety considerations associated with autonomous vessels, supporting the development of best practices and regulatory measures for safe navigation around USVs. By sharing these experiences, mariners will play a critical role in enhancing awareness and ensuring that the transition to greater autonomy at sea prioritises safety for all.

Situational Awareness- Autonomous vessels can be very small – keep a good lookout and refer to AIS and Notices to Mariners to identify if they are operating or being trialled near your area of operations.

Communications- It might feel counterintuitive or unreasonable but do contact the vessel by VHF if in doubt regarding their intentions.