The fish was swimming slowly through the very shallow water with the outgoing tide. There was a strong wind blowing as well that was pushing the fish up onto the sand. When it was in slightly deeper water it was swimming with the tide and wind and when it started to get shallow it looked like it was floundering but would appear to use its front fins. I am unsure if it was weak or was just trying to appear like weed being tossed about because it was moving through very shallow water, on top of sand, so no concealment for it from a myriad of birds around the place.