Ja, davon hatte ich auch gehört. Ob der zum Baden wirklich attraktiv ist, muss man selbst sehen. Diese Beschreibung ist vielleicht hilfreich:
Sunbathing at Banj Beach
Until recently, Sibenik didn’t have a beach within walking distance from the city center. That all changed this year, with the opening of Banj Beach, a waterside playscape complete with a volleyball court, a bar, and a pebble beach offering fantastic views of old town Sibenik.
Because Banj is on a brackish bay where the Krka River flows into the Adriatic, the water isn’t as clear or clean as what you might find on a proper coastal beach. Still, that doesn’t deter beach-goers from enjoying a refreshing dip. If you don’t feel like getting in, bring a book and enjoy the view. ;-)
http://www.likecroatia.com/news-tips/a-perfect-day-in-sibenik/