Life Jackets and MOB Systems

Life jackets and MOB systems (Man Overboard) form an inseparable safety pair in regatta sailing: the jacket keeps the person afloat and reduces exhaustion, while MOB equipment and protocols ensure the crew can find the person again and bring them back on board in time. In a dense fleet, at high boat speed or in rough seas, neither a jacket alone nor an improvised manoeuvre is enough – both must work together, be practised regularly and checked before every race.

This guide explains which life jacket types are used in competition, how MOB systems are set up technically and organisationally, and which checklists professional crews go through before the start and after every training session. It complements the overview of Safety on Board with a specific focus on personal buoyancy and man overboard recovery.

Why Life Jackets and MOB Systems Belong Together

A man overboard incident unfolds in seconds: fall, separation from the boat, drifting in wind and waves. Without a life jacket, survival time drops dramatically – especially in cold water. With a jacket alone, there is still a risk of losing sight of the person if the boat sails on or visibility is restricted by waves and spray.

Important: The life jacket buys time; the MOB system brings the person back on board. Both must work before the first signal – not only when someone goes overboard.

The Three Phases of a MOB Incident

Immediate response – shout “Man overboard!”, assign a pointer, mark the position, stop the boat or sail back to the victim.
Stabilisation – keep the person in the water, secure buoyancy, prevent hypothermia, prepare radio/SAR.
Recovery – deploy MOB equipment, bring the person on board, provide first aid.

MOB Chain from Life Jacket to Recovery

1

Fall – person leaves the boat, raise the alarm

2

Jacket provides buoyancy – secure survival time and visibility

3

MOB marking – deploy Dan Buoy or AIS, fix position

4

Boat returns – initiate Quick-Stop or return manoeuvre

5

Recovery on board – complete Lifesling, ladder or boarding

Life Jackets in the Regatta Context

Requirements for life jackets arise from class rules, Notice of Race and Sailing Instructions and national regulations. The overview of Life Jackets and Equipment describes the regulatory side; here the focus is on the optimal combination with MOB technology.

Newton Classes and Typical Regatta Use

Buoyancy

Jacket Type

Typical Regatta

MOB Relevance

50 N

Fixed foam jacket

Youth dinghies, sheltered waters

Short rescue distances; safety boat often in sight

100 N

Automatic or hybrid jacket

Olympic classes, inshore fleet races

Standard for ILCA, 470, 49er; minimal restriction of movement

150 N

Offshore jacket with hood

ORC offshore, long-distance regattas

Long rescue times; often combined with harness and Lifesling

275 N

Special offshore

Extreme offshore, cold water

Mandatory for OSR Category 1–2; MOB bearing and EPIRB essential

Automatic vs. Manual Inflation

In regatta dinghies, automatic inflatable 100 N jackets dominate: they interfere minimally with hiking and trapeze work and inflate reliably on water contact. On keelboats and offshore racers, hybrid systems are common – automatic inflation plus manual override.

Automatic jackets provide immediate buoyancy in case of unconsciousness and high freedom of movement – standard in Olympic classes. Manual systems avoid false activations with intensive water contact and are suitable for frequent capsize training without constant cartridge changes.

Jacket and Harness: Combining the Safety Harness Correctly

On keelboats and larger racers, safety harnesses connect the crew to the boat via jacklines. The jacket must be compatible with the harness – straps must not cross and must not block either inflation or the grip for manual inflation.

Route harness strap under the jacket or through integrated loops – follow manufacturer instructions.
Carabiner hooks on fixed attachment points (padeyes), not on unsecured lifelines.
Choose short tether length to minimise going overboard; long tethers only for special offshore setups.

A safety harness without a functioning life jacket and without an MOB protocol can make going overboard even more dangerous – the person hangs in the wash and cannot swim.

MOB Systems: Technology and Procedure

MOB systems comprise all means by which a crew can find a person who has gone overboard, stabilise them in the water and bring them back on board. In regatta sailing, boat-specific solutions are distinguished for dinghies, inshore keelboats and offshore racers.

Basic Equipment by Boat Type

Boat Type

MOB Marking

Recovery

Organisation

Dinghy

Visual pointer, safety boat

Capsize boat and right it; crew pulls person in

Single or double-handed crew; short communication paths

Keelboat Inshore

Dan Buoy, MOB buoy, throw bag

Quick-Stop, Lifesling, boarding ladder

Roles: pointer, helm, headsail, backstay operator

Offshore Racer

AIS-MOB, Dan Buoy, GPS marking

Lifesling, rescue ladder, possibly liferaft

Radio/DSC, EPIRB, detailed MOB briefing before leg

Important MOB Components in Detail

Dan Buoy and throw bag mark the position and connect the boat to the person. Lifesling (rescue ring with tow line) brings the person on board – before offshore races, untangle the line and check the winch. AIS-MOB transponders send GPS distress signals in poor visibility. Jacklines secure the crew on deck and are prevention, not a substitute for MOB manoeuvres.

MOB Equipment on Board

1

Dan Buoy at stern – within reach, line running free

2

Lifesling in locker – untangled, winch checked

3

Throw bag at helm – packed and throwable

4

Jacklines on deck – tensioned, carabiners checked

5

AIS-MOB in jacket – battery charged, registered

6

Radio/DSC distress call – protocol defined in crew briefing

MOB Protocols and Crew Roles

A MOB manoeuvre rarely fails due to missing equipment – more often due to unclear roles and lack of training. Professional crews define before the race:

Who shouts “Man overboard!” and keeps the pointer on the person?
Who takes helm and sails?
Who throws Dan Buoy or throw bag?
Who prepares Lifesling and recovery?
Who informs race committee or rescue coordination centre by radio?

Quick-Stop vs. Return Manoeuvre

Quick-Stop (bear-away tack) – bear away immediately, genoa backed, boat stops near the person; standard on keelboats in inshore regattas.
Figure-8 manoeuvre – classic sailing school method; takes more time but is easy to train.
Deep beam reach return – in stronger wind and larger boats; balance of speed and control.

Tip: Practise MOB manoeuvres under real conditions – with jacket in the water, in wind and light seas. A dry walk-through on land is not enough for competition.

Communication and Emergency Chain

In regattas with safety boats and Safety Rules on the Water, a tiered reporting chain often applies: crew rescues first on their own, while radio/DSC contacts race committee or coast station in parallel. In case of serious injury or failed recovery: Abandonment and Postponement of one's own participation is secondary – rescuing the person has absolute priority.

Checklists: Before the Start and After Training

Life Jacket Checklist (Each Person)

Jacket fits according to manufacturer size chart (chest circumference, weight)
CE marking and Newton class comply with SI/class rules
CO₂ cartridge within expiry date, indicator intact
Straps and buckles without tears, securely fastened
Automatic inflation tested (test mode or training)
Jacket worn throughout the entire race, not only at the start
With AIS-MOB: battery charged, device registered and paired

MOB System Checklist (Boat)

Dan Buoy or MOB buoy within reach, line running free
Throw bag packed and throwable
Lifesling untangled, winch mechanism functional
Jacklines tensioned, padeyes and carabiners checked
Boarding ladder or recovery point marked
MOB roles assigned in crew briefing
Radio/DSC distress call protocol discussed with crew
MOB drill completed in the last four weeks

MOB Briefing Before Regatta Start

Role assignment defined (pointer, helm, Lifesling operator)
Pointer rule: keep person in sight until recovery is complete
Quick-Stop procedure discussed with crew
Dan Buoy position and throw responsibility assigned
Lifesling operator and recovery point clarified
Radio channel and distress call protocol confirmed
Safety boat contact and reporting chain known
Abandonment criteria in case of injury agreed

Training and Regular Practice

MOB systems gather dust without practice. Recommendation for regatta crews:

Monthly – short briefing and visual check of all MOB equipment on board.
Before season start – full MOB manoeuvre with person in the water (jacket mandatory).
Before offshore legs – night MOB simulation or blind manoeuvre with AIS-MOB test.
After equipment change – test new jacket, new cartridge or new Lifesling immediately in training.

MOB reaction time: Untrained crews need on average approx. 90–120 seconds until the boat stops. Trained crews achieve this in approx. 30–45 seconds. Regular training significantly shortens reaction time.

Typical mistakes: pointer loses sight of the person, boat sails too far away, Lifesling is not secured, jackets are removed “because of good weather”. An MOB system only helps if the crew has practised it beforehand.

FAQ: Frequently Asked Questions About Life Jackets and MOB Systems

Is a 50 N jacket enough for regattas?

Only if SI/class rules explicitly allow it; otherwise 100 N or more.

Must I wear my jacket throughout the entire race?

Yes, if SI requires it; recommended always from 12 knots of wind.

What is more important: Quick-Stop or Lifesling?

Both; Quick-Stop brings the boat back, Lifesling brings the person on board.

How often to change CO₂ cartridge?

Immediately after every activation; check expiry date annually.

Who is responsible for the MOB pointer?

Define before the race; often helmsman or dedicated role.