TC Master 500 Gross Tonnage, Domestic (TM500D)

Correct: In a partially filled compartment, the liquid is free to move as the vessel heels. This shift of weight toward the low side of the vessel creates a ‘virtual’ rise in the center of gravity (G). This virtual rise reduces the Metacentric Height (GM), which is the primary measure of a vessel’s initial stability, making the ship more likely to capsize or develop a dangerous list.

Incorrect: Focusing only on the total weight of the liquid fails to account for the dynamic shift of the liquid’s center of mass, which is often more dangerous than the weight itself. The strategy of assuming the center of buoyancy shifts to the high side is incorrect because buoyancy actually shifts toward the submerged side of the hull. Choosing to prioritize lower total weight over the free surface effect ignores the fact that even a small amount of shifting water can significantly reduce the vessel’s ability to return to an upright position.

Takeaway: The free surface effect causes a virtual rise in the center of gravity, significantly reducing a vessel’s initial stability and metacentric height.

Correct: Applying direct pressure is the most effective initial method for controlling external hemorrhage. It physically compresses the damaged blood vessels and encourages the formation of a blood clot to stop the flow.

Incorrect: Opting for a tourniquet immediately is generally reserved for catastrophic injuries where direct pressure is likely to fail or cannot be applied. Relying solely on pressure points is no longer recommended as a primary technique because it is often ineffective and difficult to maintain. Choosing to elevate the limb without first applying direct compression does not provide enough force to stop arterial bleeding.

Takeaway: Direct pressure is the primary and most effective first-line treatment for controlling severe external bleeding in maritime emergencies.

Correct: In accordance with United States Coast Guard safety standards and survival craft operating procedures, lifeboats are equipped with an emergency steering arrangement, usually a tiller, for use if the primary mechanical linkage fails. Engaging the emergency tiller directly to the rudder stock allows the coxswain to maintain positive control and navigate the craft away from hazards like the parent vessel’s hull or suction zones.

Incorrect: Relying on a sea anchor is a tactic for reducing drift and stabilizing the craft in heavy weather but does not provide the active steering necessary to navigate away from a drifting ship. The strategy of using engine cooling water as a thruster is technically unfeasible as the discharge force is insufficient to overcome the momentum and surface area of a loaded lifeboat. Choosing to move occupants to shift weight is an ineffective method for steering a heavy, enclosed survival craft and introduces significant stability risks and potential for injury in rough seas.

Takeaway: Operators must immediately transition to emergency tiller steering if the primary helm fails to maintain maneuverability during abandonment maneuvers.

Correct: Under U.S. regulations for GMDSS, vessels operating in Sea Area A3 must ensure the functional availability of their radio equipment. This is achieved by employing at least two of the three specified methods: duplication of equipment, shore-based maintenance (SBM), or at-sea electronic maintenance. If one terminal in a duplicated system is failing, the vessel must ensure its maintenance plan or remaining equipment still satisfies the redundancy requirements to ensure distress alerting capability is never lost.

Incorrect: Relying solely on VHF DSC is an incorrect approach because Sea Area A3 operations require long-range alerting capabilities that VHF cannot provide. The strategy of seeking a verbal waiver from the Captain of the Port is invalid as GMDSS equipment requirements are statutory and typically require formal written exemptions from the FCC or USCG. Choosing to use a standard satellite phone as a substitute is insufficient because such devices do not meet the specific GMDSS technical standards for automated distress priority and maritime safety information reception.

Takeaway: Vessels in Sea Area A3 must ensure GMDSS availability through at least two methods: duplication, shore-based maintenance, or at-sea maintenance capability.

Correct: Under U.S. Coast Guard regulations and the Maritime Transportation Security Act, MARSEC Level 2 signifies a heightened risk of a security incident. The transition requires the implementation of additional protective measures beyond the baseline. This specifically includes increasing the frequency and detail of screenings for personnel, baggage, and vehicles, as well as enhancing the monitoring of restricted areas to ensure unauthorized access is prevented during the period of increased risk.

Incorrect: Focusing on full-scale drills and radio silence is a misinterpretation of the immediate operational requirements for access control and surveillance during a level change. Implementing a total lockdown with continuous armed guards is typically an extreme measure associated with MARSEC Level 3 or specific high-risk scenarios rather than the standard transition to Level 2. Simply maintaining baseline protocols with frequent electronic system tests fails to address the mandatory increase in physical security presence and screening activities required by federal maritime security standards.

Takeaway: MARSEC Level 2 necessitates increased screening frequency and enhanced surveillance to mitigate a heightened risk of security incidents in U.S. waters.

Correct: Under United States Coast Guard regulations found in 46 CFR, hydrostatic release units that are not of the disposable type must be serviced at an approved servicing facility at intervals not exceeding 12 months. This ensures that the pressure-sensitive mechanism will reliably release the life raft if the vessel sinks, even if the crew is unable to manually launch the craft.

Incorrect: Waiting for the next annual Coast Guard inspection is an incorrect approach because the equipment is already legally out of compliance once the 12-month window closes. Linking HRU maintenance solely to the five-year life raft inflation test is a dangerous misconception that ignores the specific, shorter mandatory service cycle for release mechanisms. The strategy of assuming a two-year validity period for domestic coastal operations is incorrect, as federal safety standards for these critical components do not grant extensions based on the vessel’s operational route or proximity to shore.

Takeaway: Non-disposable hydrostatic release units on US vessels must be professionally serviced and recertified every 12 months to ensure emergency functionality.

Correct: Under United States Coast Guard regulations for tankers, fully enclosed lifeboats must be equipped with a self-contained air support system to provide breathable air for the occupants and the engine. Additionally, an external water spray system is required to create a protective film over the craft, allowing it to safely transit through areas of burning oil or intense radiant heat.

Incorrect: Relying solely on heat-reflective paint and manual pumps is insufficient because it does not address the critical need for a breathable atmosphere or active cooling during a fire. The strategy of using an open-top ventilation hatch is hazardous in a fire scenario as it would allow toxic smoke and heat to enter the cabin. Choosing to rely on emergency oars and mechanical steering fails to provide the necessary speed and thermal protection required to escape a fire-affected zone on the water.

Takeaway: Fully enclosed lifeboats on tankers must provide an internal air supply and external water cooling for fire protection.

Correct: Under 46 CFR regulations, the muster list (Station Bill) is required to specify substitutes for key personnel. This ensures that if a leader, such as the Master or Chief Engineer, is incapacitated, there is a pre-established chain of command to maintain safety operations. This requirement is a fundamental component of maritime risk management and emergency preparedness.

Incorrect: Relying on the inclusion of home contact information is incorrect because the muster list is designed for immediate shipboard response rather than shore-side administrative tasks. The strategy of assigning fire-fighting duties to only one department is flawed as maritime safety requires an all-hands approach where all crew members are trained for specific roles. Choosing to delay updates until a specific turnover threshold is met is dangerous and violates the requirement to keep the muster list current for the crew actually on board.

Takeaway: USCG regulations require muster lists to identify substitutes for key personnel to ensure continuous leadership during maritime emergencies.

Correct: In accordance with United States Coast Guard (USCG) requirements for survival craft equipment, a signal mirror is a vital non-expendable tool. Unlike flares or smoke signals, which have a limited burn time and expiration date, a mirror can be used indefinitely as long as there is sunlight. It produces a high-intensity flash that can be seen for many miles, often reaching the visual horizon, making it one of the most effective long-range daylight signals available to survivors.

Incorrect: The strategy of using a mirror in dense fog is incorrect because the device relies on the reflection of direct sunlight and clear atmospheric conditions to be effective. Relying on an internal battery-powered light source describes a flashlight or strobe light rather than a standard heliograph. Focusing on infrared satellite detection is a misconception, as signal mirrors are intended for visual detection by pilots or lookouts on surface vessels rather than triggering electronic satellite sensors.

Takeaway: Signal mirrors offer a persistent, long-range daylight signaling capability that does not expire or exhaust after a single use like pyrotechnics.

Correct: Under United States maritime safety standards and Occupational Safety and Health Administration (OSHA) guidelines, hot work in or adjacent to spaces containing flammable materials requires a formal hot work permit. For spaces adjacent to fuel tanks, a Marine Chemist or a designated competent person must verify the area is gas-free to prevent explosions caused by heat conduction through the metal bulkhead, which can reach the flashpoint of vapors on the opposite side.

Incorrect: Relying solely on increased ventilation in the immediate work area is insufficient because it does not address the explosive vapors that may be trapped in the adjacent enclosed space. The strategy of placing a fire watch inside a hazardous fuel compartment is extremely dangerous and violates fundamental confined space entry and fire safety principles. Focusing only on fire-resistant coatings on the welding side fails to provide a guaranteed thermal barrier and does not meet the regulatory requirement for gas-free certification of high-risk adjacent areas.

Takeaway: Hot work near flammable storage requires formal permit authorization and verification that adjacent spaces are gas-free to prevent accidental ignition.

Correct: According to USCG and international maritime safety standards, an immersion suit must be capable of being unpacked and donned by a person without assistance within two minutes. This ensures that in a rapid-onset emergency, crew members can protect themselves against hypothermia quickly. The suit is designed to be worn over normal clothing and provides sufficient buoyancy and thermal protection on its own.

Incorrect: Allowing five minutes for donning is insufficient for emergency scenarios where every second counts toward survival in frigid waters. Keeping the suit vacuum-sealed is a dangerous practice because it prevents the mandatory periodic inspections and familiarization drills required by safety regulations. Making unauthorized modifications like adding lead weights is strictly prohibited as it compromises the buoyancy characteristics and safety certification of the equipment.

Takeaway: Immersion suits must be donned within two minutes without assistance to ensure immediate protection against cold water shock and hypothermia.

Correct: Modern EPIRBs with integrated GPS provide the most accurate and automated way to alert the U.S. Coast Guard of a survival craft’s exact location, significantly reducing the search area compared to non-GPS units by providing coordinates directly to satellite networks.

Incorrect: The strategy of using dead reckoning is prone to massive errors in small survival craft because of the unpredictable effects of wind and current on a light vessel. Choosing to rely on visual bearings is limited by the craft’s low height of eye and is often impossible when out of sight of land or in heavy fog. Opting for celestial navigation is technically demanding and requires specific environmental conditions and equipment that are rarely available or practical during a high-stress maritime emergency.

Takeaway: Integrated electronic positioning systems like GPS-enabled EPIRBs are the primary and most reliable method for locating survival craft.

Correct: The closed-loop communication method, or ‘repeat-back’ protocol, is a fundamental safety practice in United States maritime operations. It ensures that the receiver has heard and correctly interpreted the sender’s message, which is vital in high-noise and high-stress environments like an engine room fire. Using standardized marine terminology further reduces the risk of ambiguity or misinterpretation among a diverse crew.

Incorrect: The strategy of providing exhaustive technical details during an emergency broadcast can lead to information overload and distract personnel from essential life-saving actions. Relying on coded signals or jargon is dangerous because it can lead to confusion among crew members who may not be familiar with the specific codes, potentially delaying the response. Choosing to broadcast instructions only once is a significant safety failure, as the sound of the general alarm or machinery often necessitates multiple clear repetitions to ensure everyone on board has received the message.

Takeaway: Effective emergency communication requires standardized terminology and closed-loop verification to ensure all personnel accurately receive and execute critical safety orders.

Correct: Under United States Coast Guard standards, the signal mirror is one of the most powerful daytime tools for long-range signaling in sunny weather. Once the aircraft is alerted, the orange smoke canister provides a high-contrast, persistent visual reference that helps the pilot track the vessel’s exact position despite wind or sea state.

Incorrect: The strategy of using red star shells during the day is inefficient because pyrotechnic light is significantly less visible in bright sunlight compared to smoke. Focusing only on audible signals like fog horns is ineffective for aircraft communication due to engine noise and altitude. Choosing to use flags provides a static signal that may not be noticed by a pilot scanning a large area. Opting for handheld red flares in daylight lacks the contrast provided by smoke, and dye markers can be easily obscured by wave action.

Takeaway: Daytime distress signaling to aircraft is most effective when combining high-reflectivity mirrors with high-contrast orange smoke.

Correct: Providing clear, calm instructions to the casualty helps manage shock and ensures they do not inadvertently worsen their injury. Using standardized maritime terminology with the winch operator prevents confusion during critical maneuvers, ensuring the lifting sequence is synchronized with the vessel’s motion and the casualty’s position.

Incorrect: Focusing only on the winch operator neglects the casualty’s need for guidance, which can lead to panic or non-compliance during the lift. Relying on hand signals alone is dangerous in maritime environments where spray, lighting, or physical obstructions can lead to miscommunication. Assigning the least experienced crew member to handle the casualty risks providing incorrect medical or procedural information during a high-stakes situation.

Takeaway: Clear casualty reassurance combined with standardized technical commands ensures both victim safety and operational efficiency during maritime rescues.

Correct: The Very High Frequency (VHF) band, particularly Channel 16 (156.8 MHz), is the designated international and U.S. standard for distress, safety, and calling. It provides reliable line-of-sight communication, which is essential for on-scene coordination between survival craft, the parent vessel, and responding Search and Rescue (SAR) units as mandated by the FCC.

Incorrect: Relying on the Medium Frequency (MF) band at 2182 kHz is inappropriate for handheld survival craft devices because it requires significantly larger antennas and is designed for medium-range rather than short-range tactical communication. The strategy of using the High Frequency (HF) band is specialized for long-range, transoceanic communication and does not serve the purpose of localized coordination during an abandonment. Selecting the Ultra High Frequency (UHF) 406 MHz band is incorrect because this range is dedicated to Emergency Position Indicating Radio Beacons (EPIRBs) for satellite-based alerting and does not support two-way voice communication.

Takeaway: VHF Channel 16 is the mandatory frequency for short-range, line-of-sight distress and safety voice communications during marine emergencies in the United States.

Correct: Gradual rewarming of the core is the safest method to prevent afterdrop, a condition where cold blood from the extremities returns to the heart and causes a further decline in core temperature. Keeping the victim in a horizontal position is critical to maintaining stable blood pressure and preventing circulatory collapse during the rewarming process.

Incorrect: Providing alcohol is a dangerous misconception because it causes peripheral vasodilation, which actually accelerates core heat loss. The strategy of using hot water immersion for rapid rewarming can lead to a sudden drop in blood pressure known as rewarming shock. Choosing to massage the limbs is hazardous as it forces cold, acidic blood from the extremities back to the heart, which can trigger lethal cardiac arrhythmias.

Takeaway: Treat severe hypothermia by gradually rewarming the core and keeping the victim horizontal to prevent fatal circulatory complications.

Correct: Standard U.S. maritime first aid protocols for chemical skin exposure prioritize immediate and prolonged irrigation with water. This action dilutes the hazardous substance and physically removes it from the skin surface. Water is the preferred decontaminant because it is non-reactive and effectively stops the progression of tissue damage.

Incorrect: Applying a neutralizing agent is discouraged because the resulting chemical reaction can produce heat and cause secondary thermal burns. Applying a topical steroid cream immediately is inappropriate as it does not remove the irritant and can trap the chemical against the skin. Covering the area with an airtight plastic wrap without prior irrigation seals the hazardous substance against the tissue, which significantly increases the risk of severe dermatological injury.

Correct: In the event of life-threatening arterial hemorrhage, the primary objective is to stop the bleed immediately using direct pressure and, if necessary, a tourniquet placed between the wound and the heart. Under maritime medical protocols and STCW standards, once the life threat is stabilized, the next step is to seek professional guidance through Radio Medical Advice (RMA) or a tele-medical assistance service to coordinate further care or evacuation.

Incorrect: Focusing on wound sterilization and infection prevention is a secondary concern that must wait until active, life-threatening bleeding is controlled. The strategy of administering medications that interfere with clotting is clinically contraindicated in trauma cases as it would exacerbate blood loss. Choosing to apply only light distal wraps and delaying medical consultation until reaching port ignores the immediate risk of hemorrhagic shock and the necessity of timely intervention in a remote environment.

Takeaway: Life-threatening hemorrhage must be controlled with direct pressure or a tourniquet before addressing secondary medical concerns or infection risks.

Correct: VHF communications are based on line-of-sight propagation, where the range is determined by the height of both the transmitting and receiving antennas. Because a handheld radio in a survival craft is used near the water’s surface, its radio horizon is much closer than that of a ship’s mast-mounted antenna.

Incorrect: Attributing the range limitation to ionospheric D-layer attenuation is incorrect because VHF frequencies typically pass through the ionosphere rather than being reflected or significantly absorbed by it. Suggesting that seawater salinity absorbs the signal is a misconception, as VHF waves travel through the air and are blocked by the Earth’s curvature rather than being absorbed by the water itself. Focusing on ground wave propagation is inaccurate because VHF is a space-wave frequency band and does not utilize ground wave or skywave modes for standard marine communication.

Takeaway: The effective range of VHF handheld radios in survival craft is primarily restricted by the low antenna height above the sea surface.

Correct: Sounding tanks and monitoring air pipes is the standard procedure recognized by the U.S. Coast Guard for detecting flooding in spaces without direct visual access. Escaping air from a vent pipe, often heard as a whistling sound, is a primary indicator that water is entering a sealed compartment and displacing the air within, providing a rapid assessment of hull integrity.

Incorrect: The strategy of opening watertight doors is extremely hazardous because it eliminates the vessel’s primary defense against progressive flooding and could lead to a total loss of buoyancy. Focusing only on bilge manifold pressure is unreliable as it requires the pumps to be active and assumes the breach is in a space connected to the bilge system, which many voids are not. Choosing to shift fuel to adjust trim is a stability management technique rather than an assessment tool and could dangerously mask the effects of free surface water or worsen a list.

Takeaway: Initial hull damage assessment relies on manual soundings and vent monitoring to detect flooding while maintaining internal watertight boundaries.

Correct: According to US maritime safety regulations and emergency procedure standards, the Muster List or Station Bill must be kept current, and all personnel must be familiar with their specific duties before the vessel gets underway. Assigning clear roles and verifying that individuals understand their specific tasks—such as operating fire pumps or preparing survival craft—is essential for a coordinated and effective emergency response.

Incorrect: The strategy of delaying formal orientation until the first week of the voyage creates a significant period of risk where crew members are unprepared for immediate hazards. Relying solely on the observation of senior ratings during a real emergency is dangerous as it leads to confusion and potential failure of critical safety tasks. Choosing to provide manuals for independent study is insufficient because it fails to verify the crew’s physical ability to locate stations and execute manual emergency procedures correctly.

Takeaway: Every crew member must be assigned specific duties and verified as competent in those roles before the vessel departs for sea.

Correct: According to 46 CFR regulations, all life-saving equipment must be maintained in a serviceable condition and must bear a legible USCG approval label. If the label is missing or unreadable, the equipment no longer meets the legal requirements for carriage because its compliance with manufacturing standards cannot be verified.

Incorrect: Relying on minor cosmetic issues like fabric fading is incorrect because surface discoloration does not necessarily compromise the buoyancy or structural integrity of the device. The strategy of questioning storage locations is misplaced, as keeping life jackets in marked, accessible lockers with other survival equipment is a standard and accepted practice. Focusing only on the absence of a light is insufficient for condemning the jacket itself, as lights are often separate components that can be replaced or may not be required for all vessel types or operating conditions.

Takeaway: A life jacket is legally unserviceable and must be replaced if its USCG approval label is missing or illegible.

Correct: Effective Crew Resource Management (CRM) in maritime emergencies focuses on maintaining situational awareness through structured communication and proper delegation. By establishing a closed-loop communication protocol, the Master ensures that information is received and understood without becoming overwhelmed by tactical details. Delegating the tactical execution to the scene leader allows the Master to maintain the ‘big picture’ perspective necessary for overall vessel safety and coordination with external authorities like the U.S. Coast Guard.

Incorrect: The strategy of taking direct control of the nozzle team is a failure of delegation that causes the Master to lose situational awareness of the entire vessel’s safety. Choosing to move the Chief Engineer to the bridge during an engine room fire removes a critical technical expert from the location where they are most needed to manage machinery and fuel systems. Opting for a total suspension of radio traffic prevents the bridge from receiving life-safety updates and ignores the dynamic nature of maritime emergencies which require timely, verbal information exchange rather than delayed written reports.

Takeaway: Successful maritime CRM requires maintaining situational awareness through structured, closed-loop communication and delegating tactical tasks to qualified team leaders during emergencies.

Correct: Implementing a relief rotation is a critical human factors strategy that ensures personnel can recover cognitively and physically from the high-stress environment. Designating a safety officer to monitor for stress-induced errors provides an objective layer of oversight, as individuals under extreme stress often fail to recognize their own performance degradation or ‘task saturation.’

Incorrect: The strategy of keeping personnel at stations until the end of the event ignores the physiological limits of the human body and significantly increases the risk of accidents due to exhaustion. Relying solely on senior officers for manual labor is inefficient and leads to the rapid exhaustion of the vessel’s primary decision-makers who are needed for high-level oversight. Opting for increased radio traffic often creates excessive noise and information overload, which further overwhelms the crew’s processing capacity during high-stress moments.

Takeaway: Effective emergency management requires proactive rotation of personnel and objective monitoring to prevent fatigue-related errors during long-duration incidents.

Correct: According to United States Coast Guard regulations and international standards adopted by the U.S., weekly inspections require that lifeboat and rescue boat engines be run for a minimum of 3 minutes. This ensures the engine is in good working order and capable of starting in an emergency, provided the weather conditions allow for safe operation.

Incorrect: Requiring a full-throttle run for 15 minutes is not a standard weekly requirement and could lead to engine damage if the boat is not in the water. The strategy of draining and refilling fuel tanks weekly is an unnecessary maintenance burden that is not mandated by safety regulations. Opting to lower the boat into the water and maneuver it for a specific distance describes a quarterly drill requirement rather than a routine weekly inspection of the engine’s mechanical readiness.

Takeaway: United States maritime regulations require lifeboat engines to be run for at least three minutes during weekly routine inspections.

Correct: US Coast Guard regulations under 46 CFR require the muster list, commonly known as the Station Bill, to define the specific emergency duties for every person on board. This includes their assigned station for various emergencies and their specific role in operating survival craft or fire-fighting equipment to ensure a coordinated response.

Incorrect: Tracking credential expiration dates is a regulatory compliance and human resources function rather than an emergency duty. The strategy of listing medical chest contents is a requirement for the vessel’s medical log and safety equipment inventory but is not part of the Station Bill. Focusing on owner and insurance contact information is necessary for administrative and legal purposes but does not assist in the immediate tactical response to a shipboard emergency.

Takeaway: The Station Bill must clearly outline individual emergency tasks and muster stations to ensure crew readiness and safety during an incident.

Correct: Dry chemical extinguishers discharge a fine particulate that remains suspended in the air. In enclosed areas, this cloud quickly obscures the operator’s line of sight and can irritate the respiratory system, making it difficult to see the fire or locate exits.

Incorrect: Describing the agent as a shock hazard is inaccurate because dry chemical agents are non-conductive and specifically rated for Class C electrical fires. Claiming the agent causes immediate oxygen depletion confuses dry chemical with carbon dioxide or other gas-based smothering agents. Suggesting a violent reaction with lubricants is incorrect as dry chemicals are designed to safely extinguish flammable liquid fires without adverse chemical reactions.

Takeaway: Dry chemical discharge in confined spaces creates visibility and respiratory hazards that can hinder firefighting efforts.

Correct: According to U.S. Coast Guard stability principles, the free surface effect occurs when a liquid is free to move within a compartment. As the vessel heels, the liquid shifts to the low side, moving the center of gravity off the centerline. This results in a virtual rise of the center of gravity (G), which reduces the metacentric height (GM) and diminishes the vessel’s overall stability and righting energy.

Incorrect: The strategy of assuming increased displacement improves stability is incorrect because the shifting weight of the water creates a destabilizing moment that outweighs the benefit of a lower center of buoyancy. Relying on the idea that ingress water acts as beneficial ballast is a dangerous misconception; while the weight is low, its mobility creates a virtual rise in the center of gravity. Focusing only on structural stress from hydrostatic pressure ignores the more immediate risk of capsizing due to the loss of transverse stability caused by the moving liquid.

Takeaway: Free surface effect causes a virtual rise in the center of gravity, significantly reducing a vessel’s metacentric height and stability during flooding.

Correct: Under GMDSS protocols recognized by the FCC and USCG, the distress alert should be initiated via Digital Selective Calling (DSC) on Channel 70. Holding the dedicated distress button for at least five seconds ensures the automated alert, which includes the vessel’s MMSI and position, is transmitted. Once an acknowledgment is received or a short period has passed, the master should follow up with a voice Mayday call on VHF Channel 16 to provide specific details about the emergency.

Incorrect: Prioritizing voice calls over digital alerts fails to utilize the automated, data-rich capabilities of DSC which can reach further than voice in poor conditions. Attempting to use Channel 70 for voice communication is a technical error because this frequency is strictly reserved for digital data exchange and does not support voice transmission. Choosing to use an urgency signal like Pan-Pan on a bridge-to-bridge channel like 13 is inappropriate for a distress situation where there is a grave and imminent threat to life or the vessel.

Takeaway: Initiate distress alerts via DSC on Channel 70 before following up with a voice Mayday call on VHF Channel 16.