Dameisha Beach is Shenzhen's best-known urban beach, easy enough to reach from the city and popular for a quick seaside escape. Its convenience is also its weakness: on weekends and holidays it can be very crowded, and the water is not always inviting.
Go for the sea air, the broad sand, and the change of pace from downtown Shenzhen rather than for a pristine beach day. If you want a quieter coast, Xichong is usually the better deliberate trip.