A:
The Outcast Fish Cat 4-LCS Float Tube only has two chambers. I do not believe that any float tube is Coast Guard approved and I have never heard of any float tube having four actual chambers. The Outcast's Fish Cat 4 Deluxe LCS Float Tube has an inflatable seat and backrest; but these cannot be considered as Chambers.
It is always advisable to wear a Personal Floatation Device (PFD) while using a float tube and this should be Coast Guard approved. I suggest that you buy a PDF that is not too bulky or long, to give you maximum freedom whist in the tube, but ensure that it is still suitable for your weight.