Tried Williamstown Beach myself the other day, and it definitely attracts the crowds. The water is cold when you first get in, and then the whole experience is peaceful. Watch out for the rocks and bits of seaweed once you start getting deeper into the water.
May not be the best beach for the surfer types, yet this beach is fantastic for immersing yourself in water with great company, playing a few games of beach volleyball away from the deep end and a great beach to go swimming. Just be careful of the wind.
The back side of the beach features an ice cream van that sells this amazing gelato that is hard to buy (in the rainbow variety, so you get to taste all the different flavours) anywhere else in Melbourne; orange, lemon and chocolate are some of the combined flavours. This ice cream at Williamstown Beach is extremely colourful, and for only $4 a pop good, it is value to be enjoyed.