With 172,000 acres, there are lots of places to go in Biscayne National Park. Visitors with boats have full access to most of the park, although the shallow nature of the bay and reefs can preclude larger vessels. Those without a boat of their own will find many activities available at Convoy Point, including offices of the Biscayne National Underwater Park, Inc., the park's sole authorized concessioner. This is the place to make arrangements to take a guided snorkeling or glass bottom boat trip, an excursion to one of the park's islands, or to rent a canoe or kayak to explore the park's shoreline.