Whoever decided to put hot tubs in this prison was a genius and Gaeta, stripped down to a pair of swim shorts and wholly unselfconscious about the tacky, fist-sized tattoo of a tiger on his chest, is enjoying the fruits of their brilliance. It's easy to forget that this is just as much a prison as MarinaNova.
He catches sight of Martha and waves to her. The thought of asking if she'd like to join him occurs to him, but not everyone is as comfortable being in close quarters with scantily-clad near-strangers as the crew of the Galactica is. Such a thing might be misconstrued.