Less than a mile (1.6 kilometers) to Watermelon Cay, the sandy beach of Leinster Bay serves as the starting point for an approximately 10-minute swim to the island. Or, consider booking a private boat charter for the day to explore the waters of St. John. If you choose to swim, keep watch for the first glimpses of marine life among the seagrass. It’s not uncommon to see turtles, stingrays, sea cucumbers, and giant starfish.
The south- and east-facing sides of Waterlemon Cay are bordered by the region’s shallow fringe reef, whereas the west and north sides are deeper. The reef is the best spot to look for an abundance of colorful fish, which range from large parrotfish to schools of bright blue tangs. Some snorkelers swear they can hear the crunch of parrotfish “teeth” as they grind their beaks on the rocks and dead coral — try to listen and catch the sound yourself.
There are no facilities at Leinster Bay’s beach, so be sure to bring what you need with you.
Be careful not to step on coral or a resting stingray in the shallow waters.
The western side of Waterlemon Cay has an offshore current, which is stronger during new and full moons.
On the deeper side of the reef, you’ll find coral, sea fans, sea plumes, and other colorful fish. Also, keep an eye out for eels in deep holes and octopuses.
Waterlemon Cay can only be accessed by water, either via swimming from Leinster Bay’s beach or boating. It’s a 20-minute drive from Cruz Bay (where the ferries dock) to Leinster Bay, and the beach is about a mile (1.6 kilometers) hike from the Annaberg Sugar Plantation parking lot.
If you want to see the island from a different perspective, the Leinster Bay Trail, which runs along the coast of St. John, starts at the Annaberg Ruins. It eventually turns into the Johnny Horn Trail. After about a mile (1.6 kilometers), make a left turn to reach the viewpoint overlooking Waterlemon Cay.
If you’re trying to score the best photos of Waterlemon Cay, hike the Leinster Bay Trail in the morning around sunrise. Avoid heading there in the afternoon—this is when the reflection off of the water is harsh, which makes it hard to snap good photos. Keep in mind that peak season for St. John is mid-December through April; July through November is hurricane season.
Located on St. John, near Waterlemon Cay, the Annaberg Plantation Ruins are the site of a former sugar mill, slave quarters, and more. Visitors can explore the ruins along a trail marked with placards that describe how sugar was produced and explain the history of the island’s sugar plantations. Travelers say that it’s an easy walk through the site.