Path 3 — Medical & first response
Triage at sea
Module 3.18 min5-question check
Module 3.1
Prioritising care when demand exceeds capacity

In a large rescue operation, more people may need medical attention simultaneously than the medical team can treat individually. Triage — from the French trier, to sort — is the process of categorising patients by the urgency of their need so that limited medical resources are directed where they save the most lives.

Triage is led by a single trained person — supported by the medical team. On some vessels, trained non-medical crew may be asked to perform it. Whether or not that is your role, understanding the system prevents well-meaning interference that disrupts it — and helps you support the process effectively when it is under way.

What you'll cover
  • What triage is and why it is necessary
  • The four triage categories — T1 through T4
  • How triage is applied in a maritime SAR context
  • Your role in supporting (not disrupting) the triage process
Medical disclaimer
This module provides awareness-level medical knowledge — not training. It does not qualify you to perform triage, make clinical decisions, or substitute for first aid training. All medical decisions aboard are made by qualified medical staff. If your organisation requires formal first aid certification, complete that training before your deployment.
Path summary
Path 3 — Medical & first response
This path covers 5 modules: Triage at sea, drowning and water rescue medicine, hypothermia, medical emergencies, and psychological first aid. Awareness-level — know what you're seeing and what to do next.
View full path summary →
Estimated time
8 minutes — followed by a knowledge check
Section 1 of 3
What triage is — and why it matters

Without triage, medical resources in a mass casualty situation are distributed based on who arrives first, who shouts loudest, or who happens to be near the medical team. This results in resources being used on minor cases while critical cases deteriorate — and in more people dying.

Triage directs resources systematically. A patient triaged as T3 (minor) is not being neglected — they are being correctly identified as stable enough to wait while more critical cases are treated first. This is a professional and ethical decision, not indifference.

The primary survey — the first few seconds

The primary survey is a rapid assessment used at initial triage. It happens in the first few seconds — a trained medical staff member scans for immediate life threats: major haemorrhage first, then Airway, Breathing, Circulation (ABC). This immediate scan determines triage category before any detailed assessment. It is performed by trained medical staff.

Dynamic triage — categories change

Triage is not a fixed decision. A person's condition can deteriorate or improve. Someone triaged T2 may become T1. Medical staff reassess continuously during the operation. Categories are marked visibly on survivors where possible — using coloured tags (T1 red, T2 yellow, T3 green, T4 black) or other markers — so any team member can identify priority at a glance.

The goal of triage
The goal is the greatest good for the greatest number — not the most intensive care for individuals. This ethical framework is sometimes in tension with the instinct to do everything for every person. Understanding this helps you work within the system rather than against it.
Section 2 of 3
The four triage categories

Standard triage uses four categories. These are internationally consistent — the same framework is used in disaster response, military medicine, and maritime SAR.

T1
Immediate — must be treated within minutes
Requires immediate medical intervention to survive. Any problem with airway, breathing, or circulation (including severe bleeding), or the unconscious patient. These cases receive first attention.
Red tag. Examples: drowning, severe bleeding, severe hypothermia, emergencies of pregnancy or childbirth, major injuries.
T2
Delayed — must be treated within minutes to short hours
Significant medical need but condition is stable enough to wait for treatment without immediate life risk. Requires monitoring. These cases will deteriorate if not treated but are stable for now.
Yellow tag. Examples: moderate fuel burns, non-life-threatening wounds, moderate hypothermia, fractures. Note: significant dehydration can be T1.
T3
Minor — can wait hours or more
Minor injuries or medical needs. Can wait for treatment and may be able to assist others or self-care with guidance. Often the largest group in a mass casualty situation.
Green tag. Examples: minor cuts, mild dehydration, seasickness, minor anxiety.
T4
Expectant — unsurvivable given available resources
Injuries so severe that survival is unlikely even with maximum medical intervention, given the resources available. This category is extremely distressing to apply — but directing scarce resources to T1 and T2 cases saves more lives overall.
Black tag. Examples: prolonged submersion with cardiac arrest, catastrophic injuries that cannot be survived.
T4 — a difficult category
T4 is the category most likely to disturb crew who witness it. It means a person is not receiving active treatment while others are. In a mass casualty situation this category can include children — which is among the most difficult realities in emergency medicine. Understanding why — that the same resources applied to a T1 case will save a life that cannot be saved with T4 — does not make it emotionally easy. This is one of the realities of mass casualty medicine. Talking about it with your team and in debrief is important.
Section 3 of 3
Triage in the maritime SAR context

Maritime SAR triage has specific features that differ from land-based mass casualty situations.

How survivors are marked
Triage categories are recorded visibly so any team member can identify priority at a glance. Methods include coloured tags, coloured wristbands, or — if nothing else is available — a marker pen on skin. Most vessels also assign a designated physical area of the deck to each category, so survivors can be grouped by priority. Your vessel will have a specific MCI plan. Find out what system your vessel uses during your induction and review the MCI plan before you need it.
Pre-boarding triage

RHIB crew make a preliminary assessment before survivors come aboard — identifying visible critical cases and persons in the water. This pre-boarding assessment allows the medical team on the mother vessel to prepare for what is arriving. RHIB crew use a radio to pass this information to the bridge and medical team.

Persons in the water

Recovering someone from the water is an immediate priority — it takes precedence over almost everything else. Once aboard, triage follows the same algorithm as any other survivor. Someone who is walking and talking is T3. Someone unresponsive is assessed for T1. In a mass casualty situation, resuscitation is sometimes attempted if resources allow and the person was recently seen alive — this will be decided on a case-by-case basis by the medical team.

Limited resources at sea

A humanitarian SAR vessel has limited medical equipment compared to a hospital. The medical team works within these constraints. Medical evacuation (MEDEVAC) to a hospital — by helicopter or faster vessel — is requested for cases that exceed vessel capacity. The SARCO coordinates this with the MRCC.

Your role during triage

If asked by the medical team to assist — holding a patient, helping someone move, fetching equipment — do exactly what you are asked and nothing more. CPR is physically exhausting, and in a mass casualty situation the medical team may recruit general crew to rotate through compressions so the medical team remains free for clinical tasks. If asked to assist with CPR, you will be supervised and directed by medical staff throughout.

You may also be assigned to manage T3 (green) survivors — the walking wounded. This is an active role: providing basic reassurance and psychological support, watching for signs of deterioration, and keeping people within the designated area. A T3 person who deteriorates needs to be reported to the medical team immediately. Do not assume someone is fine because they were triaged green.

Do not perform medical interventions beyond your training. Do not argue with triage decisions. If you observe something the medical team has not — a person hidden or overlooked — report it clearly and directly.

Psychological impact of witnessing triage
Witnessing mass casualty triage — particularly T4 decisions — can be deeply affecting for crew who are not medical professionals. This is a normal response to an abnormal situation. Talking about it with your team, in debrief, and with support services if needed is not a weakness. It is how the psychological cost of this work is managed sustainably.
Practice — interactive
Triage a mass rescue scenario

Eight survivors have just arrived aboard from an overcrowded boat. The medical team needs you to help with preliminary sorting before formal triage. Read each survivor's presentation and assign them to the correct category.

How to use this exercise
On mobile: Tap a survivor card to select it — a row of category buttons (T1–T4) will appear. Tap the category you want to assign them to. The card will move into that bin.

On desktop: Click a survivor card to select it, then either use the category buttons or click directly into a triage bin. Work through all eight survivors, then click Review my triage to see how you did. You can reset and try again.

Your classification won't be used operationally — this is a learning exercise. Think about what you've read in the previous sections before deciding.

For reference, the NHS Ten Second Triage (TST) tool is one example of a rapid triage algorithm that may be used in mass casualty situations.

Assign selected survivor to:
Survivors waiting for assessment 8
T1 Immediate
Life-threatening, treatable now
T2 Delayed
Serious but stable
T3 Minor
Walking wounded
T4 Expectant
Unsurvivable with available resources
Knowledge check
Before you move on

Five questions on triage awareness.