Man Overboard Procedure
The person who does not fall overboard has to do all the work. This is the drill, and what each piece of electronics genuinely contributes.
The uncomfortable arithmetic of a man overboard on a shorthanded boat: the person best able to handle the situation may be the one in the water, and the person who remains has to do everything.
That is why this is a drill rather than a plan.
#What each piece of equipment actually contributes
| Equipment | Contributes | Limit |
|---|---|---|
| MOB button | A position anchor, instantly | Where they were, not where they are |
| AIS MOB device | An updating position, to your own AIS | Needs AIS aboard and the device fitted |
| PLB on the person | Satellite SAR alerting | Does not help your boat find them |
| DSC VHF | Alert with MMSI, position, time | Line of sight |
| Autopilot | Nothing — it is an obstacle here | Know how to release it instantly |
| Thermal camera | Real help at night | Only on boats that carry one |
The safety equipment guide sets out how these layers fit together. The short version for this scenario: AIS MOB devices on the lifejackets are the highest-value electronic addition a shorthanded boat can make.
#The drill
#Immediately, in this order
- Shout — "man overboard", loudly, so everyone knows
- Press the MOB button — on the nearest display, without hunting for it
- Throw buoyancy — lifebuoy, horseshoe, dan buoy, with a light. Even if it lands short
- Appoint a spotter who does nothing else and does not look away
Those four things happen in the first fifteen seconds. Everything after them is recoverable; failing them is what turns a recovery into a search.
#Then
- Take manual control. Disengage the autopilot deliberately. Know how it releases under load — this is a commissioning item, not something to discover now.
- Navigate to the AIS MOB position if there is one, not the mark
- Alert. DSC distress or urgency. Early. It can be cancelled
- Approach slowly, downwind or down-current, person on the side you can reach, engine stopped or neutral before they are alongside.
- Recover with mechanical advantage.
- Treat for cold shock, and keep monitoring
#The two things crews get wrong
Losing visual contact. A head in a moderate sea disappears astonishingly fast. The dedicated spotter is not a nicety — it is the difference between a recovery and a search. If contact is lost, the MOB mark and the AIS position are all you have.
Assuming the lift will work. A wet adult in foul weather gear is heavier than almost anyone expects, and may be unable to help. If you have not hauled a weighted practice load aboard using your actual rig, you do not know whether your recovery method works. Most crews who try it are surprised.
#Night changes everything
At night the spotter has almost nothing to point at, and the night navigation guide explains why: no depth perception, no distance estimation, and unlit objects invisible.
What helps:
- Lights on the buoyancy you throw, and on lifejackets
- AIS MOB devices — they work regardless of visibility, which is exactly when a spotter cannot
- Thermal imaging, if fitted. This is the scenario where it earns its cost
- Harnesses and jackstays rigged before dark — because not going in the water is the whole strategy
#Practise it
Once a season, in calm water, with a fender and a weighted bucket:
- everyone presses the MOB button
- everyone disengages the autopilot under way
- run the approach
- actually haul the weight aboard with your real recovery gear
- time it
The drill takes twenty minutes and is the only way to find out that your boarding ladder does not reach far enough below the waterline.
#Bottom line
Shout, press, throw, spot — in the first fifteen seconds. Then navigate to the AIS position rather than the mark, alert early, approach under control with the engine neutral, and recover with mechanical advantage you have already tested.
Common questions
Short answers to the questions this guide raises most often.
What does the chartplotter MOB button actually do?
It marks the position at the moment you press it and usually starts a bearing and range to that mark. That is genuinely useful as an anchor point, but understand its limit: it records where the person was, not where they are. Wind and current move a person in the water, so the mark becomes progressively less accurate — which is precisely why an AIS MOB device that transmits the person's own updating position is the most effective electronic aid available to a shorthanded boat.
Is an AIS MOB device better than a PLB for man overboard?
For recovery by your own boat, yes. An AIS man-overboard device alerts vessels in AIS range — including yours — with a position that updates, which is exactly what you need to get back to the person. A PLB alerts the satellite search and rescue system, which matters if the vessel cannot recover them. They solve different halves of the problem, and offshore boats commonly carry both.
Should I send a DSC distress alert for a man overboard?
On a shorthanded boat, alert early. A DSC distress or urgency alert costs nothing to send and can be cancelled once you have the person aboard, whereas a delayed alert costs response time you cannot recover. Confirm the MMSI is programmed and the radio has position before you ever need it.
How do I get an unconscious adult back aboard alone?
With mechanical advantage, rigged and practised beforehand. Assume hand-hauling is impossible — a wet adult in foul weather gear is far beyond most single crew. A halyard and primary winch with a recovery sling, a purpose-made lifting system, or a boarding ladder with a step well below the waterline are the realistic options, and all of them need to have been tried in calm water first.
Continue building the system
These guides pick up where this one stops.
Seamanship & Safety
EPIRBs, beacons and safety equipment
A beacon is the one piece of equipment whose entire value is realised in the worst moment. Registration, accessibility and crew knowledge matter as much as the hardware.
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Navigation redundancy that actually works
Redundancy is not buying two of everything. It is preventing one failure from removing several critical capabilities at once — which means the best backup usually looks nothing like the primary.
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Night and poor-visibility navigation
After dark the boat has not changed, but almost everything about how you navigate it has. Screen brightness, watch discipline and radar habits decide how safe the night is.
Read the guideEquipment & Sensors
Marine autopilot guide
On a shorthanded offshore yacht the autopilot is often the hardest-working system aboard. The control head matters least; the drive, the heading source and the sizing matter most.
Read the guideEquipment & Sensors
Marine VHF and DSC in Australia
VHF remains the primary local marine communication system, and Australia's radio framework changed in 2025 — older advice about individual station licences can now mislead.
Read the guideBy Vessel Type
Cruising sailing yacht navigation system
A cruising yacht should not be equipped like a fishing boat with a mast. Limited power, heel, exposed helms and long autopilot duty cycles change every priority.
Read the guideReferenced by
Other guides that depend on the ideas on this page.
This guide is independent editorial information, not a substitute for official regulation. Equipment requirements, licensing and chart currency differ by jurisdiction and change over time — confirm the current position with the AMSA, the Australian Hydrographic Office, ACMA and your state or territory maritime authority before relying on it.