While Cha-Am successfully caters for foreign tourists, it remains a Thai resort, with a large majority of Thai tourists. So if you are looking for the "real Thailand", for an "authentic experience", well this is it! However, the sea isn't really crystal clear, so if you want to do some diving or snorkelling, you should go further down south, to an island like Ko Tao or Ko Pha Ngan. Please also note that there is hardly any nightlife in Cha-Am. There are much better places elsewhere if you are after partying and nightlife action.
Thai people visiting Cha-Am usually come from Bangkok for the weekend. So the beachfront is very quiet during the week, and gets more animated during the weekends and national holidays. No need to say, Cha-Am is THE place to go if you are travelling with your Thai wife or Thai family. They will love it and they will feel comfortable here, which is not always the case in other popular resorts. Cha-Am is also ideal for western families, as there are a lot of activities for children and no bar scene like in Pattaya or Phuket. Expats and long term tourists in Cha-Am are mostly retirees from Northern Europe (Scandinavia, Netherlands...).