A perennial favorite for the “Best Beaches in the World” lists, Magen’s Bay won’t disappoint if it’s aesthetic sun and sand you are looking for.
Easy enough, with no hidden hazards around the entrance, although it can be a beat to windward to make it all the way up to the southeast corner of the beach. As you get close to the beach, be aware that there is a substantial sandbar in the center of the bay, 50-70 yards off the beach, with only 3-6 feet of water.
If you have a shallow-draft boat and the swell is down, you could conceivably anchor anywhere outside the swimming area that runs the full length of the beach, avoiding the shallow sandbar in the middle. But most boats gravitate to the southeast corner of the bay, for better depth and access to the dinghy channel/landing area on that end of the beach. Holding is excellent in 5 to 35 feet of water and deep sand.
Stroll the beach, go for a run or swim, and when you work up an appetite (or thirst), take care of that at the small beach bar and restaurant. This beach can get periodically quite busy with day trip traffic from the cruise ships over in Charlotte Amalie, but if you just wait a bit, they will all disappear in the afternoon just as quickly.
Walking the full length of this shore, almost a mile of perfect white sand and excellent swimming. Pull up a towel under a palm and soak it all in. This truly is the stuff Caribbean dreams are made of.