Khmer (Cambodian) New Years is coming up fast. April 13th to 15th is the official New Year, however New Years really starts about April 10th until the 20th.
The biggest Cambodian holiday is the biggest vaction time in SihanoukVille. Most (many times ALL) hotels are booked solid, and many increase their prices for the New Years celebration. Best to book a room in advance for lower rates, and guaranteed availability.
The Resorts all have special beachside dining and activities during New Year. If you're walking around town or on a public beach, be prepared to get wet. The tradition is to throw, (or squirt) water on passersby. The beaches and restaurants will be full.
Also, best to reserve your transportation here a few days in advance, as it's difficult to get on a moment's notice.
It's a fun time to be in SihanoukVille, so come check it out if you get the chance!
more info on SihanoukVille Beach Resorts website.