Vasai, Maharashtra
A life jacket that is too big rides up round the face; one that is too small may not hold its wearer high enough. Size is set by the wearer’s body weight first, and every jacket is labelled with the range it is meant for. This post explains the classes and lists MM’s range by user weight.
The SOLAS size classes
| Size | Wearer’s weight | Wearer’s height |
|---|---|---|
| Infant | Under 15 kg | Under 100 cm |
| Child | 15 kg to under 43 kg | 100 cm to under 155 cm |
| Adult | 43 kg or more | 155 cm or more |
Jackets listed against EN ISO 12402 rather than SOLAS state their own user-weight range on the label, which is the figure to match to the wearer. The SOLAS requirements post covers the rest of what a SOLAS jacket must do.
What does 150 N mean?
A buoyancy figure in newtons is the lift the jacket gives in water, not the heaviest person it can carry. A body is mostly water, so in water an adult needs only a modest amount of extra lift; the newton figure says how much the jacket supplies. EN ISO 12402 groups jackets by that figure: 50 N buoyancy aids for swimmers near help, 100 N for sheltered water, 150 N for general offshore use, and 275 N for extreme conditions and heavy clothing. The buoyancy guide works through it with real weights.
MM’s range by user weight
The table below is drawn from MM’s catalogue data: size, user weight, PFD type and buoyancy for each jacket and work vest.
| Model | Buoyancy | PFD type | User weight | Size | Standards |
|---|---|---|---|---|---|
| Saviour | 275 N | – | – | Adult | SOLAS LSA Code, BS EN ISO 12402:2020 |
| MMLJ | 240 N | I | Up to 140 kg | Adult | IRS Type Approval, SOLAS LSA Code |
| MMLJC | 90 N | I | Up to 43 kg | Child | BS EN ISO 12402:2020, PFD Type I, CE |
| SAILOR | 120 N | III | Up to 100 kg | Adult Universal | BS EN ISO 12402:2020, PFD Type III, CE |
| SEA HORSE | 70 N | III | Up to 70 kg | Adult Universal | BS EN ISO 12402:2020, PFD Type III, CE |
| SIGMA | 150 N | III | Up to 140 kg | Adult Universal | IRS Type Approval, SOLAS LSA Code, BS EN ISO 12402:2020, PFD Type III, CE |
| SOLDIER | Adjustable, 70–160 N | III | 60–130 kg (unequipped to heavily equipped) | Adult Universal | BS EN ISO 12402:2020, PFD Type III, CE |
| STELLAR | 120 N | III | Up to 95 kg | Adult Universal | BS EN ISO 12402:2020, PFD Type III, CE |
| STERN | 120 N | III | Up to 120 kg | Adult Universal | BS EN ISO 12402:2020, PFD Type III, CE |
| STERN WITH HEADREST | 120 N | III | Up to 120 kg | Adult Universal | BS EN ISO 12402:2020, PFD Type III, CE |
| SUMO | 150 N | III | Up to 140 kg | Adult Universal | BS EN ISO 12402:2020, PFD Type III, CE |
| SUMO WITH HEADREST | 150 N | III | Up to 140 kg | Adult Universal | BS EN ISO 12402:2020, PFD Type III, CE |
| MMWVCG | 78 N | V | Up to 56 kg | Adult Universal | SOLAS LSA Code, CE, PFD Type V |
| MMWV | 100 N | III | Up to 90 kg | Adult Universal | BS EN ISO 12402:2020, PFD Type III, SOLAS LSA Code, CE |
The Sea Master is listed in four tiers, from adult down to infant, each with its own weight limit, buoyancy and ISO class:
| Specification | Value |
|---|---|
| Adult Universal | Up to 95 kg · PFD III · 100 N · ISO 12402-4 |
| Child Large | Up to 80 kg · PFD III · 100 N · ISO 12402-4 |
| Child Junior | Up to 36 kg · PFD III · 50 N · ISO 12402-5 |
| Child Infant | Up to 14 kg · PFD III · 50 N · ISO 12402-5 |
| Accessories | Life jacket light / buddy line (optional) |
Sizing a crew or a group
- Size for the heaviest person who will wear each jacket, and check that weight is inside the label’s range.
- Order children’s and infants’ jackets as their own sizes; an adult jacket cinched tight is not a child’s jacket.
- For larger wearers, look for the universal adult jackets with the highest user weight: MM lists the Sigma, the SUMO and the MMLJ to 140 kg.
- Fit each jacket on the person: fastened, it should not ride up past the chin when lifted at the shoulders.
Weights and buoyancy figures are as listed in MM’s catalogue; standards named are as stated by MM. Tell us how many people of which weights, and we will match the models: request a quote.