Start hereRules checked 20 October 2026
A marine evacuation system (MES) is the big inflatable slide or chute you see in a box on the side of a ferry or cruise ship. Pull the handle and, in a few minutes, a passage unrolls down the ship’s side to a floating platform, liferafts inflate alongside, and hundreds of people slide or drop into them. Hardly anyone on board has seen it happen.
That is the problem the rules try to solve. An MES is serviced every year, but the only time anyone finds out whether it really deploys is at installation and at its rotational test deployment, at least once every six years. The UK raised unsuccessful MES deployments at the IMO’s Maritime Safety Committee, and both the UK and the Bahamas now collect a report on every deployment, graded as a pass, a partial pass or a fail.7 This lesson walks you through the decisions an operator and a master face around that deployment.
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In this lesson
- Planning and running a rotational MES deployment
- In plain words
- In detail
- What the rules say
- Flag and class notes
- Key numbers
- What inspectors find
- Quiz: 6 questions
Try it
Planning and running a rotational MES deployment
In plain words
An MES is a way down the ship’s side. It has a container on the ship, a passage (an inflatable slide or a fabric chute), usually a floating platform at the bottom, and liferafts that tie up to the platform. People go down the passage, cross the platform and climb into the rafts.
Two things keep it ready. Every year a service station opens, tests and repacks it, just like a liferaft. At least once every six years each MES is actually deployed from the ship, in harbour, in front of a surveyor. Ships with several systems take turns. The deployment is also the best training the crew will ever get, so as many crew as possible should take part.
When a new MES is fitted, half of them are deployed straight away and the rest within a year.
In detail
Parts and performance
The International Life-Saving Appliance (LSA) Code, section 6.2, sets the standard. An MES must:2
- be capable of deployment by one person;
- let the total number of persons it is designed for transfer into the inflated rafts within 30 minutes on a passenger ship, or 10 minutes on a cargo ship, from the abandon ship signal;
- let rafts be secured to and released from the platform by a person in the raft or on the platform;
- deploy with the ship trimmed up to 10° and listed up to 20° either way;
- if it has an inclined slide, keep the slide angle between 30° and 35° with the ship upright in its lightest seagoing condition (and no more than 55° in the final stage of flooding on passenger ships);
- give a satisfactory means of evacuation in a sea state associated with wind force 6 on the Beaufort scale;
- be evaluated for capacity by timed evacuation deployments in harbour;
- need only a minimum of routine maintenance, with parts maintained by the crew easy to reach.
The platform must be stable, self-draining, subdivided so that losing one compartment does not stop evacuation, and held by bowsing lines that deploy automatically. Rafts used with the MES must comply with the inflatable liferaft rules, drop clear of the system, be released one at a time, and have pre-connected or easily connected retrieving lines to the platform.2
SOLAS also requires no ship-side openings between the MES embarkation station and the waterline, protection from projections, clearance from the propeller and overhanging hull, and communication between the embarkation station and the platform or rafts. Everyone assigned to the MES party must have an immersion suit or anti-exposure suit of an appropriate size, unless the ship trades constantly in warm climates.4
The service cycle
| When | What | Who |
|---|---|---|
| At installation | Trial deployment of at least 50% of the systems fitted; the rest within 12 months if those are satisfactory | Crew, witnessed by flag or RO2 |
| Every abandon ship drill | Procedures up to the point just before actual deployment, backed by on-board training aids | Crew5 |
| Every 12 months (flag may allow 17) | Full service at an approved station | Service station1 |
| At least every 2 years, never more than 3 | Each MES party member trained by taking part in a full deployment into water, on board or ashore, as far as practicable | Crew5 |
| At least every 6 years for each system | Rotational deployment from the ship at intervals agreed by the Administration | Crew, witnessed by flag or RO1 |
The container and the system itself must be marked with the maker, serial number, approving authority and capacity, date of manufacture, the date and place of the last service, the maximum stowage height and the stowage position.2
Running a rotational deployment the way the flag expects
The UK and Bahamas notices are the most detailed public guidance. Together they describe this sequence:67
- Plan. Agree with the flag or RO which units will be deployed, where and when, and how many link rafts. Build spare units into the rotation so that all have similar periods between deployments.
- Invite the witness. A flag surveyor, an RO (class) surveyor or, for the Bahamas, an approved nautical inspector.
- Pre-deployment check. The manufacturer’s representative and crew make a documented visual inspection and pre-deployment checks.
- Deploy with the crew. Competent crew follow the ship’s documented procedure and the maker’s instructions. Nobody else intervenes unless there is a safety risk. The exercise may be slowed down for safety and training.
- Record. The witness notes crew competence, the number of people evacuated, the time from activation to the end of the evacuation, any modifications, workarounds or interventions, and takes photographs.
- Grade. Successful; successful by secondary means; partially successful; or unsuccessful.
- Follow up. For a failure, the manufacturer supplies a root cause analysis (the UK asks within one month) and corrective actions; the Bahamas also asks for another MES to be deployed where practicable and for any systemic fault to be reported with a list of affected ships.
- Log it. The deployment goes in the official log book, and each unit’s full service and deployment history stays on board.
What counts as a fail
A deployment is unsuccessful if any of these happened: the manufacturer or its representative had to take unplanned action during pre-deployment checks without which the system would not have deployed; departures from the maker’s launching instructions were needed to launch it; or the full capacity of the MES could not have got into the rafts in the required time. The Bahamas adds unexpected deflation of a raft or link raft.67
It is partially successful only if all three apply: the evacuation could still have been done in time; any intervention could have been done safely by a crew member; and the fault was minor enough not to worry evacuees.6
Modifications
Any change to an installed MES, even an extra bowsing line or a new structure near the deployment path, must be agreed with the manufacturer and approved by the body that type-approved the system. The MCA treats an unauthorised modification as invalidating the approval.6
What the rules say
- SOLAS regulation III/20.8.1 requires every MES to be serviced at intervals not exceeding 12 months at an approved servicing station, extendable to 17 months by the Administration where this is impracticable.1
- SOLAS regulation III/20.8.2 requires each MES to be deployed from the ship on a rotational basis at intervals agreed by the Administration, and at least once every 6 years.1
- LSA Code paragraph 6.2.2.2 requires at least 50% of the MES on a ship to be deployed after installation, and the rest within 12 months.2
- LSA Code paragraph 6.2.2.1.2 requires the full rated number of persons to be transferred into the rafts within 30 minutes on passenger ships and 10 minutes on cargo ships.2
- SOLAS regulation III/19.3.4.8 (19.3.3.8 in the 1996 text) requires MES drills up to the point before actual deployment, and requires each MES party member, as far as practicable, to take part in a full deployment at intervals of not longer than 2 years, and in no case longer than 3 years.59
- SOLAS regulation III/7.3 requires an immersion suit or anti-exposure suit for every person assigned to the MES party, unless the ship is constantly in warm climates.4
- The IMO survey guidelines tell the surveyor to check the 50% deployment at the initial survey and the rotational deployment at each annual survey.3
Flag and class notes
- United Kingdom. MGN 558 (M) Amendment 1 (June 2021) says the six-year rotational deployment cannot be extended, requires an MCA or RO surveyor to witness it, sets the pass, partial and fail criteria and asks for a root cause report within one month of a failed deployment. It also recommends the same six-yearly deployments for non-SOLAS MES on UK domestic passenger ships.6
- Bahamas. Marine Notice 84 (March 2022) adds unexpected raft deflation to the fail criteria, requires deployments to be logged in the official log book, asks for a report form to be sent for every deployment and collects historical data from 2012 onwards.7
- Canada. Transport Canada’s Ship Safety Bulletin 13/2019 recommends deploying at least one MES for crew training every two years before it goes for annual servicing, and each unit at least once every six years.8
Key numbers
| What | Value |
|---|---|
| Rotational deployment of each MES | at least once every 6 years1 |
| Service interval | 12 months, flag may extend to 171 |
| Deployment after installation | at least 50% at once, the rest within 12 months2 |
| Evacuation time, passenger ship | 30 min for full rated capacity2 |
| Evacuation time, cargo ship | 10 min2 |
| Slide angle, ship upright | 30° to 35°2 |
| Design conditions | trim 10°, list 20°, wind force 62 |
| Full-deployment training for MES party | at least every 2 years, never more than 35 |
| UK root cause report after a failure | within 1 month6 |
What inspectors find
- Rotational deployment records missing or overdue, or no evidence of which unit was deployed when; surveyors check this at every annual survey.37
- Deployments “rescued” by manufacturer technicians, which the UK and Bahamas count as unsuccessful.67
- Link rafts, painters and bowsing lines snagging or jammed, and inflation faults such as perished hoses or gas flow blockages; these are among the problem categories on the MCA’s deployment report form.6
- Unauthorised changes near the MES, such as structures or lines added after installation that obstruct deployment.6
FAQ
Can a rotational deployment also be the crew's training?
Yes. SOLAS links the two, and the UK, the Bahamas and Canada all encourage using the deployment to train as many crew as possible. Agree the training plan with the surveyor and the manufacturer beforehand.
Do we need a surveyor present?
SOLAS leaves the arrangements to the Administration. The UK requires an MCA or RO surveyor, and the Bahamas a class surveyor, an approved nautical inspector or BMA staff. Check your flag’s notice.
Can we extend the annual service of an MES?
The same 17-month rule as liferafts applies, only where servicing is impracticable. The UK will consider no more than 5 months and asks for the full service history and the master’s confirmation of the MES condition.
Who repacks the MES after the deployment?
An approved service station accredited by the manufacturer, as for the annual service. The repack is often combined with the next annual service.
Quiz6 questions
Sources
- 1
SOLAS 1974, chapter III, regulation 20.8.1 and 20.8.2 (Rotational deployment of marine evacuation systems), as adopted by IMO Resolution MSC.47(66) (in force 1 July 1998). https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.47(66).pdf
- 2
LSA Code, IMO Resolution MSC.48(66), section 6.2 (Marine evacuation systems), paragraphs 6.2.1 to 6.2.5. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.48(66).pdf
- 3
IMO Resolution A.1186(33), Survey Guidelines under the HSSC, 2023, Annex items (EI) 1.1.4.19 and (EA) 1.2.2.37. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/AssemblyDocuments/A.1186(33).pdf
- 4
SOLAS chapter III, regulations 6.4.4, 7.3 and 15 (Stowage of marine evacuation systems), as adopted by Resolution MSC.47(66). https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.47(66).pdf
- 5
SOLAS chapter III, regulation 19, MES drill and training paragraph (numbered 19.3.3.8 in the 1996 text adopted by MSC.47(66); cited and quoted as III/19.3.4.8 in UK MGN 558 (M) Amendment 1, section 6.1, and in later consolidated editions). https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.47(66).pdf
- 6
UK Maritime and Coastguard Agency, MGN 558 (M) Amendment 1, Life-Saving Appliances, Marine Evacuation Systems (MES), Servicing and Deployments (June 2021), sections 2 to 7 and Annex 1. https://assets.publishing.service.gov.uk/media/60c759f6e90e0743acb7a1b7/MGN_558_Amendment_1.pdf
- 7
Bahamas Maritime Authority, Marine Notice 84, Marine Evacuation Systems, version 1.0 (14 March 2022), sections 4 to 7. https://www.bahamasmaritime.com/wp-content/uploads/2022/03/MN084-Marine-Evacuation-Systems-v1.0.pdf
- 8
Transport Canada, Ship Safety Bulletin 13/2019, Schedules of deployment for marine evacuation systems (12 November 2019). https://tc.canada.ca/sites/default/files/migrated/ssb_13_2019e.PDF
- 9
Lloyd’s Register, Guidance note: Summary of SOLAS requirements for maintenance, servicing, testing and drills (January 2020), table of on-board training and drills (MES drill and MES training, III/19.3.4.8). https://www.iims.org.uk/wp-content/uploads/2019/12/Onboard_Maintenance_Guidance_tables.pdf
Rules checked 20 October 2026. VSL Safety is not an approved training provider and doesn't issue certificates. These lessons don't replace STCW training, or the manufacturer's training and certification that service technicians need.
