The drink will be there when you get back. You dash after the umbrella and snatch it up just as it hits the water. It's useless as a decoration now. At least you're not adding the problem of oceanic garbage.
A flash of light beside you catches your eye. Curious, you poke at the mound of sand with your toe and discover the flash came from light reflecting off a glass bottle. Inside is a rolled up piece of paper.
You look around in surprise but there's no one nearby. "A message in a bottle, really?" you say, mostly to yourself. "Is this a joke?"
Given that you and Ric were the only ones in this area of the beach, and how much of the bottle was buried by the sand, it can't have been put there intentionally.