Buoyancy Rating

The  Buoyancy Aids on our website are tested and rated to specific European Standards and split into CE categories. These are the universal criteria that define each product and the environment they are suitable for. 

The level of lift (floatation) a buoyancy aid or personal flotation device (PFD) gives a body in water is known as the buoyancy rating, which is measured in Newtons.

50N = 11lbs/5kg          60N = 13.5lbs/6.1kg            70N = 16lbs/7.3kg              80N = 18lbs/8.2kg

From the chart above you might wonder how does only 5 kg of buoyancy hold up a 85kg person?
Let's do the maths to see.

The density of water is 1.00 ( meaning 1 cubic meter of water weighs 1000 kg )
The average density of the human body is 1.04
The density of polystyrene foam is 0.4

As we know that the foam floats we can see that anything with a density greater than 1.00 is going to sink in water and anything with a density less than 1.00 is going to float in water.

Therefore if we put an 85 kg human body in water the amount of water it will displace will weigh less than it's weight of 85 kg and it will sink . The difference in the weight is the minimum amount of “floatation” a bouyancy aid would have to profide to support the person:

85 kg * ( 1.04 – 1.00 ) = 3.4 kg of “floatation” needed .

In practice the clothing that is worn also provides extra “floatation”, which means that a buoyancy aid with 5kg of “floatation” will easily support an 85 kg person.

Buoyancy Aids in the ranges above are mainly used for active surface watersports such as: Dinghy Sailing, Kayaking and Kite Surfing.

Suitability:  Only suitable for competent swimmers.

Conditions:  Sheltered water use where help is close at hand.

Assurance: They give a reasonable assurance of safety from drowning in relatively calm waters

Protection:  Only provides support to conscious people who can help themselves.