Not a beach for sun basking, but you will find a few nice things near to this beach. Rawai Pier, and next to it the Fish Market. If you visit this market you will find on the right side of the street the Fish Market, left side of the street a few restaurants who will prepare the fish you buy on the market!
Rawai Beach is well known for night live, a few bars and restaurants.
But the main reason I want to bring you to Rawai Beach: you can rent a longtail boat to visit one of the Islands. They can bring you to nice snorkeling and scuba-diving spots. Ask the boat owners, they know the dive spots!
To find the cache, look for the "Stationary Shop" (Buddha Shop). It's only opened on Buddha Days, but you will find the cache under the sunshade. When it's open, have a breakfast there, you will not regret it.