ONDECK
Academy
OOW Oral Prep
Module 18 — OOW 3000 GT Oral Preparation
SAR & IAMSAR
IAMSAR Vol III · SAR coordination · Search patterns · OSC · Assisting disabled vessels and ditched aircraft · Helicopter operations
SAR Organisation — IAMSAR Framework
The International Aeronautical and Maritime Search and Rescue (IAMSAR) Manual is published jointly by IMO and ICAO. Volume III — Mobile Facilities is the volume carried on commercial vessels. It provides procedures for the OOW when involved in a SAR operation as a participating vessel.
| Organisation / Role | Responsibility |
|---|---|
| MRCC (Maritime Rescue Co-ordination Centre) | Operates 24/7 at national level. Coordinates all maritime SAR operations within a national SAR region (SRR). First point of contact for distress alerts. Designates the OSC and assigns search areas |
| MRSC (Maritime Rescue Sub-Centre) | Covers a sub-region under the MRCC. Same coordination function at regional level |
| OSC (On Scene Co-ordinator) | The designated vessel or aircraft acting as coordinator at the scene. May be assigned by MRCC or self-assigned as the first vessel on scene. Coordinates search patterns, survivor transfer, communications with MRCC. This could be you |
| ACO (Aircraft Co-ordinator) | Coordinates aircraft involved when both ships and aircraft are involved |
| Assisting vessel | Any vessel responding to a distress alert and assisting (units designated and trained for SAR are SRUs — search and rescue units). Merchant vessels are obligated under SOLAS V/33 to render assistance to persons in danger at sea |
SOLAS V/33 — duty to render assistance: The Master of a ship at sea in a position to be able to provide assistance is required to proceed with all speed to the assistance of persons in distress at sea when informed of their need. This is a legal obligation. If possible she informs the persons in distress or the SAR service that she is proceeding. If the master is unable to assist, or in the special circumstances considers it unreasonable or unnecessary, he logs the reason and informs the SAR service. The ship is released when other ships have been requisitioned and she has not, or when the persons in distress, the SAR service or a ship that has reached them say assistance is no longer needed (V/33.1, 33.3, 33.4).
Receiving a Distress Alert
| Step | Action |
|---|---|
| 1 | Note the time and position of the distress alert. Record all information received (MMSI, vessel name, nature of distress, position, number of persons) |
| 2 | Call the Master immediately |
| 3 | Acknowledge receipt — a DSC alert: do NOT acknowledge by DSC (the coast station's job); listen on Ch 16 and acknowledge by voice if no coast station or RCC has within about 5 minutes, and inform the coast station or RCC; a ship acknowledges by DSC only if a coast station or RCC directs it, and never sends an all-ships DSC distress relay (MSC.1/Circ.1657/Rev.1). A voice Mayday: acknowledge by voice on the channel it was heard on (Ch 16) |
| 4 | Plot the distress position — calculate distance and ETA at best speed |
| 5 | Alter course and increase to best speed toward the distress position (on the Master's order) — SOLAS V/33 is to proceed with all speed; do not wait for tasking to start |
| 6 | At the same time, inform the MRCC (V/33: "if possible" tell the SAR service you are proceeding) — vessel name, position, speed, ETA to the distress position, and what help you can give |
| 7 | Maintain a continuous listening watch on Ch 16 and DSC Channel 70 |
| 8 | Prepare rescue equipment — lifebuoys, lines, scrambling nets, boarding ladder, warm blankets, first aid, hot drinks |
Search Patterns — IAMSAR Vol III
| Pattern | Use | Description |
|---|---|---|
| Expanding Square (SS) | Small search area, datum well-known, single vessel | Start at datum, travel outward in expanding squares. First two legs are S (track spacing); leg length then increases by one track spacing every second leg (S, S, 2S, 2S, 3S, 3S…). Used when survivor position is known accurately — e.g. EPIRB position |
| Sector (VS) | Small datum area, position accurate, single vessel or aircraft | From datum, run out on a leg, turn 120° to starboard for a cross-leg, turn 120° again and run back through datum; three such triangles (nine legs) cover the full circle. A second search may be rotated 30°. Best for EPIRB or SART position with good accuracy |
| Parallel Sweep (PS) | Large search area, survivor location uncertain, one or more vessels | Legs parallel to each other and to the long sides (major axis) of the area or sub-area, separated by track spacing (S). Commence search point in a corner, half a track spacing in from each side. With several vessels the OSC gives each a sub-area or offset track. Efficient for large areas |
| Creeping Line, co-ordinated (CSC) | Large area, object more likely at one end; a ship and an aircraft together | Creeping line legs run parallel to the SHORT sides (minor axis), so coverage advances along the area from the most likely end. In the co-ordinated version the aircraft flies the legs while the ship steams along the major axis at the speed the OSC sets, as the aircraft's checkpoint |
| Track Line (TSR / TSN) | Craft missing on a known route | Search along the casualty's intended route. Return (TSR): down one side of the track and back up the other. Non-return (TSN): a single pass along it. Often the first search when a craft has disappeared on a known route |
Track spacing and POD: Track spacing (S) is the distance between parallel search legs. It is calculated from the search object, environmental conditions, and required Probability of Detection (POD). IAMSAR tables give track spacing values. Reducing S increases POD but takes more time — the OSC balances the two. On the OOW oral, know what track spacing means and why it matters.
OSC Responsibilities — If You Are Assigned
- Establish and maintain communications with MRCC and all SAR vessels on scene on the agreed SAR working frequency
- Determine the datum (most probable position of survivors) from last known position, time elapsed, drift tables, leeway, and current
- Calculate the search area and assign track spacing from IAMSAR tables
- Brief all vessels on the search pattern, start point, track spacing, search speed, and reporting intervals
- Coordinate survivor recovery — ensure an adequate vessel is positioned for rescue; confirm life-saving equipment is ready
- Keep MRCC informed of all significant developments — start of search, sightings, recoveries, changes to plan
- Maintain a SAR log with times, positions, decisions, and communications
- Suspend search only on MRCC authority — do not suspend independently
Assisting a Disabled Vessel
| Situation | Approach |
|---|---|
| Initial contact | Establish comms on Ch 16. Determine nature of problem, number of persons, injuries, flooding, stability, EPIRB status. Report situation to MRCC and Master |
| Provide lee | Position your vessel to windward of the casualty to create a calm water lee for small craft or persons in the water: stop well short to judge your drift, approach with the wind or sea fine on the weather bow and the casualty fine on the lee bow, then turn away from the weather and stop with her close on your lee side (MSC.1/Circ.1182/Rev.1). You usually drift faster than she does, so you close her. Manoeuvre at slow speed — prop wash and bow wave can swamp a small vessel |
| Throw lines | Pass heaving lines, then tow rope if casualty is to be towed. Brief crew — person in the water must have a line on them before you manoeuvre |
| Boarding | Only if requested and safe — do not put crew at risk to board an unstable casualty. Use the tender for boarding, not the parent vessel's side |
| Towing | See Module 19. The towing vessel tows from her stern towing point, never her bow; the casualty makes the tow fast forward to her strongest point (on a ship, classically her own anchor cable). Set appropriate tow speed for sea state |
Assisting a Ditched Aircraft
Aircraft ditching is rare but the OOW must know the immediate actions:
- Alert MRCC immediately — an aircraft casualty is co-ordinated by the RCC responsible (an aeronautical RCC or a joint RCC), working with the maritime RCC
- Plot the reported ditching position — wreckage, rafts and survivors drift downwind and with the current from the moment of ditching; expect them down-drift of the reported position, and an aircraft may sink within minutes
- Approach the scene slowly — debris and fuel may be in the water; propellers can injure survivors
- Stop engines or go to dead slow ahead when survivors are in the water near your vessel. Deploy scrambling nets and boarding ladders
- Persons in an inflated life raft — make a lee: come up with the raft fine on your lee bow, turn away from the weather and stop with it close on your lee side. Do not stop downwind and wait for it — a stopped ship usually drifts faster than a raft
- Survivor recovery sequence: hypothermia risk is immediate — get them out of the water, dry, warm, medical assessment
- Fuel contamination — aircraft fuel is extremely flammable. No smoking anywhere near the recovery area. Post fire watch
- Account for all persons from the aircraft manifest — obtain from the airline/aircraft operator via MRCC
- Maintain the scene until instructed by MRCC to stand down — there may be further survivors in the water
Helicopter Operations
Helicopter operations are one of the most hazardous activities conducted on a vessel. Every aspect of the operation must be pre-briefed, all crew assigned roles, and the operation must be conducted only after explicit clearance from the pilot. The OOW's role is to prepare the ship and coordinate with the helicopter — the pilot commands the operation from the air.
Before the Operation
- Clear and secure the landing area (if equipped) — remove all loose items, nets, aerials, lines
- Confirm wind speed and direction — helicopter needs to approach into wind. Alter course if required; liaise with pilot on preferred approach heading
- Mark the deck with a wind direction indicator (windsock or equivalent)
- Brief all crew on their roles: deck party, medical team, fire party
- Post firefighting crew with CO₂ or DCP extinguisher at the landing spot — standby throughout
- Clear the area of all non-essential personnel
- Confirm the ship's position to the helicopter by radio — give Lat/Long, wind speed and direction, and vessel course and speed
- Radar to standby (or off) as directed — a radiating scanner is a radiation hazard to the winchman and can interfere with the helicopter's systems
During the Operation
- Maintain steady course and speed — do not alter course without informing the pilot
- Static discharge: if a rescue wire is lowered, let it touch deck or water before anyone handles it — static built up on the helicopter can give a severe shock
- Do not attach the helicopter wire to the vessel — if the helicopter must break away, the wire must be free to run out
- Maintain continuous radio watch on the agreed frequency throughout
- The pilot-in-command is in charge of the operation in the air. The Master is responsible on deck. Do not act without clearance from the pilot
- Medical transfer: a stretcher case must be strapped in correctly before winching — follow the instructions of the helicopter crew/paramedic
- Log start time, end time, nature of operation, and number of persons transferred
Oral Exam Practice Questions
Question 1
You receive a DSC distress alert on Channel 70. What are your immediate actions?
Record the time of receipt and all information from the DSC alert — MMSI, nature of distress, position if transmitted. Call the Master. Do NOT acknowledge by DSC — the DSC acknowledgement is the coast station/MRCC's job, and a ship's DSC acknowledgement can cancel the alert's automatic repetition. Shift to Ch 16, listen for about 5 minutes, and if no coast station or RCC has answered, acknowledge by VOICE and tell the coast station or RCC; a ship sends a DSC acknowledgement only if a coast station or RCC directs it (MSC.1/Circ.1657/Rev.1). Plot the distress position on the chart and calculate distance and ETA at best speed. With the Master's agreement, alter course toward the distress position and increase to best speed — SOLAS V/33 says proceed with all speed, so we do not wait for tasking — and at the same time call MRCC: our vessel name, position, speed, ETA to the distress position, and ask for instructions. If the Master decides we cannot or should not proceed, the reason is logged and MRCC told. Prepare rescue equipment — lifebuoys, throwing lines, scrambling nets, boarding ladders, medical kit, warm blankets. Maintain continuous watch on Ch 16 and DSC Ch 70.
Question 2
You are the first vessel on scene following a capsize. There are approximately 15 persons in the water. MRCC has designated you as OSC. What does that mean and what do you do?
OSC — On Scene Co-ordinator — means I am now responsible for coordinating the SAR operation at the scene on behalf of MRCC. My first priority is survivor recovery before anyone drowns or dies of hypothermia. Immediately: deploy our lifebuoys and throw lines to persons in the water. Position the vessel to create a lee — come up with the wind fine on the weather bow and the survivors fine on the lee bow, turn away and stop upwind of them with them close on the lee side, and let her drift down slowly; propellers stopped when people are close. Brief crew — deploy scrambling nets and boarding ladders, assign personnel to pull survivors from the water, assign a medical team to begin assessment and warming on board. Maintain a continuous count of persons recovered and persons still in the water. Report continuously to MRCC. As more vessels arrive, designate search sectors and assign parallel sweep patterns for persons who may have drifted. Maintain the SAR log — times, positions, recoveries, decisions. Do not suspend the search until MRCC authorises. Continue until all persons are accounted for or MRCC orders suspension.
Question 3
A medical evacuation by helicopter has been requested for a seriously ill crew member. You are on watch. What preparations do you make?
Call the Master immediately. Contact MRCC and the helicopter controller on the agreed frequency — report vessel name, position, course, speed, wind speed and direction, and nature of the medical emergency. Agree the approach heading with the pilot — the helicopter will approach into wind, so I may need to alter course. Clear the helicopter landing area or HLS (heli-hoist deck) of all loose equipment, lines, aerials, and obstructions. Set radar to standby as directed — a radiating scanner is a radiation hazard to the winchman and can interfere with the helicopter's systems. Brief the deck team: a fire party with extinguishers stationed at the landing area throughout the operation; medical team prepared to transfer the patient in a stretcher if required; all non-essential crew clear of the area. Rig a wind indicator — windsock or equivalent. Confirm the ship's details to the helicopter by radio as they approach. When the rescue wire is deployed, allow it to contact the deck first before anyone handles it — the static charge can give a severe shock. Do not attach the wire to the vessel. Maintain steady course and speed throughout — no alterations without informing the pilot. Log the entire operation with times.