http://tinamue.blogspot.com/2013/03/cambodia-sihanoukville-revisited.html
The beaches of Sihanoukville are beautiful, superb, unspoiled, and relatively unused although the main beach can get crowded on weekends. Here in the rainy season, they are not much of an attraction because when it rains in Sihanoukville, it pours.
However, if you visit during the dry and warm seasons head east of town. There you will soon leave the crowds behind you while the beauty of the beach increases. Soon you will end at an estuary where your main risk is to have the tranquility disturbed by a herd of cows.
There are also beaches to the west of Sihanoukville – for
example, Hun Sen Beach located a few kilometers before the oil depot - that are
totally deserted. Almost no tourists venture west of the Port of Sihanoukville.
The most likely reasons are that the first kilometers of road are in a terrible
state of repairs and that this first stretch of road goes through slum-like fishing
villages. Those facts will deter most tourists daring to venture outside of town on their own.