There are regular local buses from surrounding resorts into Nesebar. If you are on a package holiday in one of the nearby resorts, the rep may try to sell you an excursion to Nesebar on the basis that local buses are unreliable, confusing and expensive; ignore them. You can get buses to Nesebar that are clearly marked in English from numerous bus stops along the main road, and they only cost a few stotinkis.
You can also get a tourist boat from Sunny Beach to Nesebar; this is more expensive and less frequent that the buses.
