This is typical for the Chesapeake Bay this time of year. These are small jellyfish we used to call sea nettles. They sting a bit, but are not dangerous. Easy to avoid.

http://coastwatch.noaa.gov/seanettles/

They have “netted off” the small beach at the hotel, but I would stick to the pools anyway. The sea nettles don’t deter water skiers.

Reminds me of an unfortunate experience I had in Maui about two years ago. They cleared out the bar 10 minutes early, and refused to give my wife a glass of champagne (her first drink of the day.) A call to the duty manager resulted in a free bottle of Dom Perignon.