Fun in Water

Satellite image from Google Earth

Providence and Santa Catalina Islands are surrounded by a 32km long barrier reef protecting the Eastern and Northern / Southern parts of the island.
It is a barrier reef akin to longer ones in Australia, New Caledonia, Meso-American (Including Belize), and Andros Island, Bahamas.

Boat Tour around the Island

A popular way of exploring Providence is to take a day long boat tour around the island.
The boat stops at Crab Cay, and then passes the Three Brothers Cay along the way to Lover's Bridge.
Stops at Manzanillo and Southwest Beaches completes the tour.
 

Crab Cay

You may take the island boat tour to get to Crab Cay or take a private boat / kayak on your own.
Crab Cay is a large rock with a small dock and hiking trail. It sits in the middle of a shallow area of the sea.
The short hiking trail to the top of the rock brings you to a 360 degree view of the barrier reef and Providence Island.
You may also snorkel near the dock or snorkel around the Cay / rock. Drinks and snacks are available at the dock area.

Kayaking

Near the posada you may rent a kayak and paddle around Santa Catalina. You may also rent a kayak
to cross the ocean between Providence and Crab Cay. It's about a 20-30 minute paddle / way in 1-2 person kayaks.
You can relax on Crab Cay then paddle back at your own leisure. Each kayak rents for about 30.000 COP / $15.

Snorkeling / Scuba Diving

Scuba diving is also popular in Providence. To learn more about the dive sites
and dive operators you may watch the video and visit the websites below.

Recommended dive shops

United Nations Biosphere Reserve.

Providence and Santa Catalina have been designated a United Nations Biosphere Reserve.
As of 2010 there are 553 biosphere reserves in 107 countries.
World_Network_of_Biosphere_Reserves (Wikipedia) - UNESCO Biosphere Reserves (UNESCO)

In the San Andres Archipelago (Wiki) it is called the Seaflower Biosphere Reserve - Seaflower (UNESCO)