How is the external flotation bladder of an immersion suit inflated?

The external flotation bladder of an immersion suit is inflated by blowing through an inflation tube. This method is designed for simplicity and reliability in emergency situations. When the wearer needs to activate the flotation feature, they can easily do so by using their breath to fill the bladder, ensuring the suit provides adequate buoyancy in the water without the need for additional equipment or complex mechanisms.

This design choice allows for quick deployment and function, especially in survival scenarios where time and ease of use are critical. Being able to easily inflate the flotation bladder with one's breath also means that even in harsh conditions, the individual can effectively prepare for flotation without relying on electricity or other tools that may not be readily available.

The other options, like using an electric pump or a handheld air compressor, may not be practical or safe in emergency situations due to power supply issues, lack of access, or potential for mechanical failure. Submerging the suit in water cannot inflate the bladder effectively, as the design specifically relies on the introduction of air to create buoyancy.