The entire process of learning to swim is considered to include two stages: - getting familiar with the water environment and movements in it; - acquiring skills in standard swimming strokes. Buoyant aids for swimming instruction (in brief: swimming device(s)) are intended to assist users (in particular children) to learn to swim. The design and purpose of the devices are related to the above stages. Swimming devices are intended to give the user positive buoyancy in the water while maintaining the correct body position for swimming. However, it should not be assumed that standard conformity of the devices will by itself eliminate the risk of drowning as this depends also on the behaviour of the user and any supervision. Although this European Standard sets performance requirements to ensure that swimming devices perform appropriately, it is essential that the devices are used correctly and under constant and close supervision. It is important to ensure that they are securely fitted to the appropriate size of user and that when correctly fitted, they cannot become displaced. Swim seats however should allow immediate escape in case of capsizing. Therefore the use of these devices is recommended to be restricted to water out of standing depth of the user. The highest degree of protection against drowning can only be achieved by using lifejackets. It is essential that there is a clear distinction between devices intended to preserve life and those which are intended only to assist buoyancy for the user when learning to swim. As swimming devices are not life preservers, they should only be used in swimming pools and other situations free from current, tides and waves. For the stated reasons and to differentiate these devices from aquatic toys, advisory safety measures, including marking, warning notices and user instructions are included in this standard. Part 1 of this European Standard only deals with devices that are securely attached to the body (class B devices = for an active user). They are intended to introduce the user to the range of swimming strokes. This standard includes safety requirements within the meaning of the Produktsicherheitsgesetz (ProdSG) (German Product Safety Act). This document (EN 13138-1:2014) has been prepared by Technical Committee CEN/TC 162 "Protective clothing including hand and arm protection and lifejackets", the secretariat of which is held by DIN (Germany). The responsible German body involved in its preparation was the DIN Standards Committee Sports Equipment (NASport), Working Committee NA 112-04-04 AA "Wasserrettungs- und Sicherheitsmittel" ("Lifesaving in water and safety equipment").