What is the difference between a buoyancy aid and a life jacket?

A buoyancy aid (50N) helps a conscious swimmer stay afloat and allows freedom of movement for active sports like kayaking. A life jacket (100N+) is designed to turn an unconscious person face-up in the water. For active paddling, a buoyancy aid is preferred. For sailing or exposed sea conditions, a life jacket is essential.

How should a PFD fit?

A PFD should be snug but not restrictive. You should be able to paddle comfortably with full arm movement. When pulled up by the shoulders, it should not ride up past your chin. Adjust all straps and test in shallow water before your trip. A PFD that rides up is dangerous as it can obscure your face in the water.

Do I legally need a PFD in the UK?

There is no UK law requiring PFDs on inland waters for adults. However, it is strongly recommended by the RNLI, British Canoeing, and all safety organisations. On commercial vessels and organised activities, PFDs are mandatory. Many waterway authorities require them. Always wear one — drowning is the leading cause of death in outdoor water activities.

What do the Newton (N) ratings mean?

50N: buoyancy aid for sheltered water and competent swimmers. 100N: life jacket for calm coastal and inland waters. 150N: life jacket for general offshore use. 275N: life jacket for extreme offshore conditions or heavy clothing. The Newton rating indicates the buoyancy force the device provides.

CampCalcs

PFD Size Calculator

Determine the right personal flotation device size based on chest measurement and weight.

Chest Circumference

Measure around widest part

Body Weight

Primary Activity

How We Calculate This

Size Determination

PFD size is based on chest circumference: XS (<80cm), S (80-88cm), M (88-96cm), L (96-104cm), XL (104-112cm), XXL (112cm+).

Buoyancy Standards (EN ISO 12402)

50N: Buoyancy aid (inland/sheltered). 100N: Life jacket (calm coastal). 150N: Offshore life jacket. 275N: Extreme conditions.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify conditions and use proper safety equipment outdoors.