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-ordinating Authority) | Coordinates aircraft involved when both ships and aircraft are involved |
| SAR Vessel (SRV) | Any vessel responding to a distress alert and assisting. 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 every ship 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. It can only be modified if rendering assistance would seriously endanger the ship, crew, or passengers, or if other vessels are already providing effective assistance.
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 — if on DSC: acknowledge on DSC, then shift to Ch 16 for voice. If voice only: acknowledge on the working channel |
| 4 | Plot the distress position — calculate distance and ETA at best speed |
| 5 | Alter course and increase speed toward the distress position |
| 6 | Contact MRCC — report vessel name, position, speed, ETA to the distress position, and number of crew available for rescue |
| 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 leg is S (track spacing). Subsequent legs increase by one track spacing. Used when survivor position is known accurately — e.g. EPIRB position |
| Sector (VS) | Small datum area, position accurate, single vessel or aircraft | From datum, travel outward on a bearing, return on a reciprocal, rotate bearing by 120°, repeat. Three sectors cover a full 360° circle. Best for EPIRB or SART position with good accuracy |
| Parallel Track (PS) | Large search area, multiple vessels, elongated datum | Vessels travel parallel tracks separated by track spacing (S). Entire area covered systematically. Used with multiple SAR vessels — OSC assigns each vessel a track. Efficient for large areas |
| Creeping Line (CS) | Elongated datum, current drift suspected, multiple vessels | Similar to PS but tracks are perpendicular to the expected drift direction. The first track is offset to one side of datum so the search starts upwind/upcurrent |
| Track Line Return (TL) | Known route or single track to search | Retrace the last known track of the casualty. Used when a vessel has gone missing on a specific passage 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. 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. Take a tow connection forward on the towing vessel — use the anchor cable or tow line via the bow roller. 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 — aircraft SAR is coordinated jointly with the national Aviation authority (ARCC)
- Plot the reported ditching position — aircraft drift rapidly downwind; approach upwind of the expected position
- 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 — approach from leeward (the raft drifts downwind toward you — less distance to swim)
- 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
- Switch off radars — radar emission can interfere with helicopter instruments and ignite fuel
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 build-up from the helicopter rotor can be lethal
- 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 in normal circumstances — within coast-station coverage 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, and acknowledge by VOICE; a ship-to-ship DSC acknowledgement is a last resort, only when no coast station has responded after several minutes and distress traffic must proceed. Plot the distress position on the chart and calculate distance and ETA at best speed. Call MRCC on Ch 16 — report our vessel name, position, speed, and ETA to the distress position, and ask for instructions. Alter course toward the distress position and increase to best speed unless instructed otherwise by MRCC or unless rendering assistance would seriously endanger our vessel. 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 — go upwind of survivors and drift toward them slowly, or come alongside if conditions allow. 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 track 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 — static discharge from the rotor can be fatal. 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.