Riva Beach Club is a popular independent beach club (ie not attached to a hotel), especially among expats. The entrance fee will score you a sunbed and towel, and access to the gym, steam rooms and a pristine 300m stretch of sand. There's a resident DJ and a separate family area and pool. The on-site Italian restaurant gets mixed reviews, but the cocktails are divine.
Riva Beach Club
Dubai Marina & Palm Jumeirah