Lifebuoys: The Distribution Rule Most Ships Get Wrong

A lifebuoy is a ring that floats. The complication is that SOLAS does not treat them as interchangeable: it specifies which buoys carry lights, which carry smoke, which carry lifelines, and, crucially, which combinations are not allowed on the same buoy.

By MarineCraft Journal  · 
15 September 2026  · 
9 mins read

Not All Lifebuoys Are the Same Lifebuoy

Walk a deck and the lifebuoys look identical. Under SOLAS Chapter III, Regulation 7, they are not. The regulation divides a ship’s lifebuoys into functional groups, each with different attachments and different stowage logic, and an inspector checking them is checking the distribution rather than counting rings.

The starting requirements are straightforward. Lifebuoys must be distributed so they are readily available on both sides of the ship and, as far as practicable, on all open decks extending to the ship’s side. At least one must be placed in the vicinity of the stern. And all of them must be stowed so they can be rapidly cast loose, and not permanently secured in any way. That last phrase is where a surprising number of findings originate, because a buoy lashed neatly into its bracket for heavy weather and never freed again is non-compliant however well maintained it is.

The Combination Rule That Catches People

Here is the provision that generates the most confusion, and the one worth knowing precisely. Not less than one half of the total number of lifebuoys must be provided with self-igniting lights. Not less than two of those must also be provided with self-activating smoke signals, and those must be capable of quick release from the navigation bridge. Lifebuoys with lights, and those with lights and smoke signals, must be equally distributed on both sides of the ship.

Then the sting: those lifebuoys must not be the ones fitted with buoyant lifelines. At least one lifebuoy on each side must carry a lifeline, and that buoy is a different buoy from the ones carrying lights and smoke.

The reasoning is operational rather than bureaucratic. A lifeline buoy is thrown to a person alongside so they can be pulled back to the ship, so it must stay attached. A light-and-smoke buoy is released from the bridge to mark a position in the water, so it must float free and drift with the casualty. A buoy tethered by a lifeline cannot mark a position, and a buoy that drifts away cannot pull anyone in. The two jobs are incompatible, which is why the regulation separates them.

The Mass Requirement Nobody Expects

A second detail that catches operators sits in the LSA Code. A lifebuoy must generally have a mass of not less than 2.5 kg. But where the buoy is intended to operate a quick-release arrangement for a self-activating smoke signal and self-igniting light, it must have a mass sufficient to operate that arrangement, or 4 kg, whichever is greater.

In practice this means the bridge-wing buoys are heavier than the rest, and substituting a lighter buoy into a quick-release bracket, which looks like sensible standardisation, defeats the release mechanism. The buoy is too light to trip it. This is exactly the kind of substitution that happens during a routine replacement and goes unnoticed until someone tests the release.

What the Attachments Must Actually Do

The performance requirements for the attachments are specific enough to test, which is why inspectors do.

Where the Findings Come From

Lifebuoy deficiencies are common precisely because the equipment is simple and the rules are not. The recurring ones are worth naming: buoys lashed or painted into their brackets so they cannot be cast loose; the wrong buoys carrying the wrong attachments, most often a lifeline on a buoy that also has a light and smoke signal; smoke signals and light batteries past their expiry, which run on their own clocks like every other pyrotechnic and battery aboard; lifelines that have perished, kinked, or been shortened; quick-release arrangements seized or obstructed on the bridge wings; and missing or illegible ship name markings.

The expiry point deserves the same treatment as the rest of the pyrotechnic inventory. Self-activating smoke signals carry manufacturer-marked expiry dates, and self-igniting light batteries have their own service life. Both sit outside the rhythm of a weekly deck round, which is how they lapse on ships that are otherwise well maintained, and both are trivially checkable by an inspector who picks one up and reads the label.

Getting the Distribution Right

The practical exercise is a distribution audit rather than a maintenance task. Count the total, confirm that at least half carry lights, confirm that at least two of those also carry smoke signals and are on quick-release at the bridge, confirm at least one lifeline buoy on each side, and confirm that the lifeline buoys are not the light-and-smoke buoys. Then check that lights and light-and-smoke buoys are balanced port and starboard, that at least one buoy is near the stern, and that the bridge-wing buoys meet the 4 kg mass for their release arrangement.

Done once properly and recorded on the fire and safety plan, that distribution holds until someone replaces a buoy. Which is the real risk: a like-for-like replacement that is not like for like, made in good faith, that quietly breaks a rule nobody rereads. Among life-saving appliances, lifebuoys are the item where the equipment is cheapest and the arrangement matters most.

Frequently Asked Questions

Sources: IMO SOLAS Chapter III, Regulation 7, Personal life-saving appliances (lifebuoy distribution, lifelines, lights, smoke signals and quick release from the navigation bridge) · IMO International Life-Saving Appliance (LSA) Code, Section 2.1, Lifebuoys (construction, mass, self-igniting lights, self-activating smoke signals and buoyant lifelines) · IMO SOLAS Chapter III, Regulation 20, Operational readiness, maintenance and inspections · IMO SOLAS Chapter V, Regulation 23, Pilot transfer arrangements (lifebuoy with self-igniting light and buoyant lifeline at embarkation points)