Staff on Rihanna's rented yacht are exhausted from the star's partying which has continued into the early hours each night.
Rihanna is keeping the crew on her holiday yacht awake with her partying.
The 24-year-old singer has booked a reported Â£100,000 cruise on the French Riviera so she and pals including love interest Drake can enjoy a fun-filled vacation but exhausted staff are struggling to keep up with her late nights.
A source told The Sun newspaper: ''The gang stayed up singing and dancing until dawn.
''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.''
Rihanna reportedly stocked up on 25 bottles of gold Armand de Brignac Champagne, 60 bottles of Peroni and Corona beer and 10 bottles of tequila.
The 'We Found Love' hitmaker has decided to give her on/off relationship with Drake another chance following the death of her beloved grandmother known as Dolly.
A source previously said: ''Rihanna is determined to live life to the full following her grandma's death and decided to give it another go with Drake.
''In the past he'd moan that she wouldn't commit and was working all the time. But she's up for trying again.
''They'll spend a week cruising around the Mediterranean.
''Rihanna wants to travel down through Italy and go to the most romantic places she's seen online.''