FAQs Lifejackets


What is the difference between 275 Newton and 150 Newton and how do I decide which I need?

The difference is the level of buoyancy or flotation provided – a 275 Newton having a higher level of buoyancy being nearly double that of 150 Newton.

A 150 Newton should only be used where light weight clothing is being worn and no heavy tools being carried. It is not recommended to the used with a flotation suit or a dry suit as it is possible that it will not self-right you in conjunction with this type of clothing.

A 275 Newton should be used where heavy weight clothing is being worn or tools are being carried, or when wearing a flotation suit of dry suit.

What is the key protection given by a lifejacket?

The key protection factors of a lifejacket are that on water immersion it will:

  • Self-right you if you fall in face-down and / or unconscious
  • Will support your head and upper torso above the water level to minimize the risk of drowning

What is the difference in weight between a 150 Newton and a 275 Newton lifejacket in its undeployed state?

Less than 30 grams, which is very little. The common perception is that a 275 Newton lifejacket is a lot heavier and more cumbersome than a 150 Newton, but this is not the case.

What does Newton buoyancy relate to?

Newton buoyancy basically relates to the amount of upward force or uplift provided by a lifejacket (or flotation suit / buoyancy aid) in the water.

1 Newton = approximately 1 tenth of a kilo (100 grams)

So a 50 Newton buoyancy aid will give 5 kilos of additional uplift in the water; a 150 Newton lifejacket will give 15 kilos of additional uplift; a 275 Newton lifejacket will give 27.5 kilos additional uplift.

Is my weight a determine factor in the selection of my lifejacket? If I am heavy in weight do I need to buy a 275 N instead of a 150 N?

Not necessarily. Generally speaking larger than average people have more inherent buoyancy in their own bodies and greater lung capacity than smaller people so the additional buoyancy required to support you in the water and self-right you is sometimes less than with a smaller person.

What lifejacket should be worn with a floatation suit?

It is strongly recommended that a 275 Newton lifejacket is worn in conjunction with a flotation suit to guarantee self-righting in the water. The inherent buoyancy in a flotation suit (or the trapped air in a dry suit) will counteract the buoyancy of a lifejacket. Consequently a 150 Newton level of lifejacket is not always guaranteed to turn you as it has less force.

How often do I have to have my lifejackets operating parts changed / what is the life on these parts?

The life / replacement period on the operating parts is as follows:

  • SOLAS light: 5 years
  • CO2 gas cylinder: 5 years
  • United Moulders Firing Cartridge: 3 years
  • Halkey Roberts Cellulose Bobbin: 2 years
  • Hammar inflation mechanism: 5 years

NB. This is assuring there is no interim damage or corrosion to these parts within this period. If there is, then they should be replaced at this point.

It is possible to purchase inflation mechanism and gas cylinders for rearming my lifejacket when it has been fired?

Yes, we supply all rearming parts required for all our lifejackets and rearming instructions can also be supplied.

How long is a lifejacket guaranteed for?

This depends on the nature and frequency of use (if being used in a leisure environment on an occasional basis and providing it is well looked after and serviced regularly then it may well last for tens of years.

If being used in a heavy duty commercial environment on a regular basis then it may only last 1 – 2 years.

Should a crutch strap be worn at all times?

It is strongly advised that it should be. Otherwise you fall into the water, the tendency will be for the lifejacket to come up over your head with the force of inflation and the impact of the water. Then your lifejacket will not be giving you the correct protection and / or supporting your head out of the water.