Can you explain the floating? Is it a lopsided float? Does it look like the turtle wants to be submerged but cant? If I had to guess as of now, I would say your right. I would take it to a vet before it gets any worse.
Chris
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0.1 Red Eared Slider, 1.0 Common Snapper, 1.0 Bearded Dragon and a 55gal Native Fish Tank with a LM Bass and Pleco.
I use to have a collection of Leopard Geckos that I bred, but have sold them.