Abstract: A device for inflating a balloon or other inflatable structure is disclosed. A neck of the inflatable structure fits through an annular mouthpiece of an oral inflator, and a check valve assembly is inserted therein, compressing the neck of the balloon between the check valve assembly and the mouthpiece and preventing air from exiting from the balloon. Air is orally introduced into the check valve to inflate the balloon. A housing may be included for containing the oral inflator and the balloon. In one embodiment, multiple balloons are fixed to multiple oral inflators, each of which is connected through an inflation manifold to an inflation tube. An flexible strap with a selectively releasable fastener on each end can be used to secure the device to a swimmer. In one embodiment, a pressurized inflation cartridge may be included that has a selectively openable valve for inflating each balloon.