From my understanding the Mosiac is a zone 9 and 10 plant so it will not overwinter here in Tennessee. I am very fortunate to have the The Water Garden here locally. The plant grows very rapidly and it only cost a few dollars so if I have to I will replace it every year. It's planted but looks like a floater. It does want full sun.
I'm hoping as the water hyacinth and water lettuce are being eliminated from pond stores that they will start to carry the mosaic plant as an alternative. Not a true floater, but a great looking plant!