This is one of the main public beaches on the island. It's about a 20-minute walk from the hostel or 10-minute bike ride. On a hot day--as most of them are--it seems like a long walk, especially as there's no pavement for half the trek. Still, it does give you a chance to get away from the tourist tack of Duval Street and check out local houses as you wander along.
Smathers Beach stretches a fair distance and the golden sand is lined with shady palm trees, a promenade, and fast-food stands. The further you walk, the less-crowded it seems to get. The beach is probably more suited to sunbathing than swimming as the water is pretty murky with seaweed and you need to watch out for jellyfish.