East of Grand Case off Orient Beach, the snorkeling at Green Cay is a popular destination. Located in Orient Bay, Caye Verte as it is also known is an easy swim from the crowded Orient Beach.
To reach the snorkeling on Saint-Martin by air, fly into Princess Juliana International Airport (SXM). Note, there is a $30USD departure tax collected at the airport.
In addition, there is a ferry called Great Bay Ferry that interconnects St. Martin with St Barts.
Overall, Green Cay is the 4th most popular snorkel dive spot of all 10 snorkeling dives in St Martin.