This document specifies the safety requirements for buoyancy aids, performance level 50. It is applicable to buoyancy aids for adults and children with a body mass greater than 25 kg only, used in sheltered waters. Buoyancy aids require active participation by the user where help and rescue are close at hand. One-piece and two-piece inherently buoyant floatation suit PFDs are deemed to qualify as special application devices according to ISO 12402-6:2020.