What is Buoyancy Requirements of Lifejacket as per SOLAS ?

1. A lifejacket shall have sufficient buoyancy and stability in calm fresh water to,– 

(a) Lift the mouth of an exhausted or unconscious not less than 120 millimetres clear of the water with the body inclined backwards at an angle of not less than 20 degree and more than 50 degree from the vertical position ; and 

(b) Turn the body of an unconscious person in the water from any position to one where the mouth is clear of the water in not more than 5 seconds. 

2. A lifejacket shall have buoyancy which is not reduced by more, than 5 per cent after 24 hours submersion in fresh water. 
3. A lifejacket shall allow the person wearing it to swim a short distance and to board a survival craft. 

You may also know about other requirements of lifejacket :