Bouyant

buoy·ant 

–adjective
1.
tending to float in a fluid.
2.
capable of keeping a body afloat, as a liquid.
3.
not easily depressed; cheerful.
4.
cheering or invigorating.

Origin: 1570–80; buoy + -ant—Related forms
buoy·ant·ly, adverb
non·buoy·ant, adjective
non·buoy·ant·ly, adverb
un·buoy·ant, adjective
un·buoy·ant·ly, adverb
—Synonyms 3. happy, lighthearted, breezy, jaunty, sunny.





url: http://dictionary.reference.com/browse/buoyant