While not a must-visit for every traveler in Venice, taking the time to make the trip (about an hour by public transport from S. Marco) is definitely worth it. You'll be rewarded with a stunning view of the Adriatic, untouched by tourists or beach clubs, just pure nature, soft sand, and windswept dunes. Take a leisurely stroll all the way south, and out onto the jetty at the end for the full experience.
While it's not the Caribbean Sea, it also doesn't have the crowded and hectic atmosphere typical of Adriatic coast beaches. It's beautiful even in winter during low tide.
There were quite a few people at the beach, which made it a bit crowded for my liking. Although the water was pleasantly warm, it lacked clarity. Additionally, the sand didn't quite meet my expectations in terms of quality.