the degree of inflation of each of the chambers 20 22 will vary the amount of buoyancy of the device 10 a central band portion 28 is disposed intermediate the upper chamber 20 and the lower chamber 22 the band portion or member 28 is preferably not inflatable and functions as a connecting member between the two inflatable chambers 20 22 as illustrated in fig1 the device 10 is slipped about the leg 12 of the user in its inflated form it is then secured and tightened to the leg by a securing mechanism 29 as more clearly illustrated in fig2 in preferred form the securing mechanism 29 includes a cord member 30 which is adapted to generally surround the band portion 28 in preferred form the cord 30 is constructed from a sturdy yet relatively thin rope material to secure the cord 30 to the member 18 a plurality of apertures 32 34 are disposed in the band 28 in this manner and as clearly illustrated in fig2 the cord 30 is laced or interweaved around band 28 by passing along the outer surface of the band through an aperture 32 to the interior surface of the band 28 and then back out through aperture 34 to the outer surface of the band 28 thus the cord 30 is firmly maintained in position about the band 28 in preferred form the band 28 has two.