Exploring the river

Exploring the River

Buoyancy Aids or Life Jackets: what's the difference?

Posted by Gav Grayston.
First Published Aug 2013; updated May 2023.

This guide helps you choose a buoyancy aid or life jacket, which one is appropriate, and what's best for children and family water sports.

It is quite common for people to call a buoyancy aid a life jacket. However, they are different. In this post, we look at those differences, what you should choose for family water activities, and what's best for younger and older children.

Buoyancy Aids or Life Jackets - what's the difference?

Essentially buoyancy aids are designed to help you swim if you capsize, whereas a life jacket is designed to keep a person afloat without swimming.

buoyancy aids are designed to help you swim if you capsize, whereas a life jacket is designed to keep a person afloat without the need to swim

This last point is important. A life jacket should keep someone afloat even if they are unconscious. They have a collar designed to keep the person's face clear of the water. They are ideal for non-swimmers.

However, you can get different types of life jackets. Some will not keep a person afloat in rough conditions or if the person is wearing lots of clothes.

What does 50N mean?

You will often see 50N on buoyancy aids and 100N or 150N on life jackets. This indicates how buoyant they are. The 'N' stands for Newton, and this is known as the 'Newton Range'.

The above is not a life jacket and should be worn by good swimmers in sheltered waters, with help at hand, though it does depend on the activity and age. ISO 12402-5

The example above is your basic life jacket which keeps a person afloat in sheltered waters. It isn’t buoyant enough to keep a person afloat who is wearing foul-weather clothing, for example. ISO 12402-4

Lifejacket with harness

The above is a life jacket 150N. If you are going offshore, where you are likely to encounter rough weather, you must get a 150N life jacket. This should keep a person afloat even when wearing foul-weather gear. ISO 12402-3

275N life jacket

The above is a Life Jacket 275N.

This level of floatation is required if you are going offshore and are likely to encounter extreme weather conditions and will be wearing extreme weather gear. ISO 12402-2

When should I use a buoyancy aid and not a life jacket?

Because life jackets are more buoyant, they can be problematic for some activities, making swimming difficult. For example, if you are dinghy sailing, then capsizing can be expected. You must swim back to your boat and right it in this situation. A full life jacket will make this more difficult.

The same is true of kayaking.

Are buoyancy aids suitable for young children?

For young children and all non-swimmers, then a life jacket is required.

Child's life jacket

This 100N child's life jacket is designed to keep their head out of the water without them needing to swim.

If you are family canoeing on calm (not too cold) waters, the adults would wear buoyancy aids, and any young children wear life jackets.

If you capsize, the adults can rescue the children and get them back into the canoe.

For our setup, our youngest children have always worn a life jacket when small and transitioned to buoyancy aids when they are older and have become good swimmers.

When not to wear a buoyancy aid

You always need to take conditions into account.

If you are sea kayaking in poor conditions, a life jacket would be more appropriate. However, you wouldn't be family sea kayaking in rough conditions, would you?

Consider the amount of clothing you wear (including shoes) and how cold the water is.

I have done whitewater kayaking in glacier meltwater. I can tell you first-hand that capsizing in water that cold can reduce your immediate reaction to swim, and very cold water can make breathing difficult and force you to take in a breath... which is not good news when you are under the water.

In very cold water, you should be wearing a winter-rated wetsuit (otherwise, hypothermia will soon set in), and wetsuits can help with buoyancy, so if you are correctly kitted out for cold weather white-water canoeing or rafting, then a buoyancy aid can still be appropriate. After all, you would be doing this activity in a group where rescue is at hand, and you wouldn't be doing it with very young children.

What to look for when buying a life jacket

Use the Newton Range to select a life jacket suitable for the activity.

When buying a life jacket for young children or babies, you must have a crotch strap (in fact, all life jackets should have this to avoid them riding up in the water) and a good collar to keep their head clear of the water.

Always choose a life jacket appropriate for the person's weight (including clothing). Life jackets should also come with a rescue whistle. Instruct your kids that this is for emergency use only.

What about automatic life jackets?

Childs automatic Life jacket

A child's automatic life jacket

You will see many adult life jackets as 'automatic' and often come with a built-in harness. These are usually slightly more expensive.

Automatic life jackets are generally used for sailing (in a yacht, not a dinghy) or power boats and will self-inflate if immersed in water.

Moving around a boat is easier with a deflated life jacket, leaving your arms free to work winches, etc. The harness element attaches to a safety line, which you use when moving around a yacht in rough conditions.

Although these life jackets will not inflate if splashed with water, they are unsuitable for dinghy sailing or kayaking, where you are likelier to end up in the water.

These types of life jackets use a CO2 cartridge to self-inflate, so using them in sports where you are more likely to end up in the water will mean you will get through a lot of CO2 canisters, as well as the disadvantages in ease of swimming and movement when inflated.

What to look for when buying a buoyancy aid

You will want to use a buoyancy aid for canoeing, kayaking, or dinghy sailing.

For these activities, you will need a jacket that doesn't restrict arm movement and comfortable to move around in.

You do not need a crotch strap, though a crotch strap can help prevent the aid from rising up when in the water. A well-fitted buoyancy aid should not do this too much.

As with life jackets, choose a buoyancy aid appropriate for the person's weight.

There are generally two different fitting types: pull over your head or zipped front.

We prefer the latter, though if you are worried that people would not do the jacket up properly, get the pull over the head type.

Other features you may find useful are buoyancy aids with pockets. You may be wearing a cag or spray top under the jacket, which often has a large front pocket but cannot be used when the buoyancy aid is on.

How much do buoyancy aids cost?

When kitting your family out, the costs can soon rise. And like everything else, some buoyancy aids are more expensive than others. Prices can start from around £35.

Use our guide above and shop around to find the right personal flotation device for your child.

Here are two that we have used and found particularly good.

The Crewsaver Junior Spiral 100N Life Jacket is something we've used when our children were young, yet we still wanted to get out canoeing on the water (in calm waters).

As our children grew and could swim, they transitioned to buoyancy aids. We found this Helly Hansen one good.