Marcus Jordan was back in Miami Beach on Sunday ... and while he hit the sand with a different woman than Saturday -- the results were largely the same.

Michael's son and his new gal pal were all over each other -- this despite Marcus having a similar afternoon with an entirely different woman some 24 hours prior.

34-year-old MJ and the Larsa Pippen lookalike -- who was wearing a tiny, baby blue bikini -- hugged on one another ... and passionately made out in the ocean as they enjoyed several hours in the South Florida sun.

Marcus, of course, was spotted doing almost the same exact activities a day prior with yet another mystery woman ... but he didn't seem to care if anyone noticed, as he flashed a big grin while paparazzi snapped pics of him from just feet away.

Marcus, of course, used to have similar outings with his ex, Pippen ... but since she's moved on with Jeff Coby, it certainly looks like he's having a tryout of sorts to find a suitable replacement.