London, July 19 :  Singer Rihanna's late night parties on her yacht around the Mediterranean are keeping the crew members awake.

"She's a lovely girl but the crew are only getting a few hours sleep a night. And they have to be prepared to be vigilant and make sure she doesn't get hammered and fall into the sea," thesun.co.uk quoted a source as saying.

"The gang stayed up singing and dancing until dawn," the source added.

Her booze tab reportedly includes 25 bottles of gold Armand de Brignac Champagne, 60 bottles of Peroni and Corona and 10 bottles of tequila, so the 24-year-old has to stay careful.

© IANS