St Kitts diving is excellent. While there are not large numbers of very large fish and other species to be seen, there is a great diversity, as well as a wide variety of St Kitts and Nevis scuba dive sites that range from colorful reef formations and exciting wrecks to steep walls and peaceful drift dives. The sport here is less developed than it is on other Caribbean islands, meaning the sites are in much more pristine condition than those areas that are more famous and more frequented. An example of this is the reef system loosely named Brimstone Shallows that sits beneath the UNESCO World Heritage Site of Brimstone Hill. The reef system here is so far reaching that it boasts many individual sites—many of which haven't even been named and others that may be referred to in several different ways. This is a moderate dive area of 50 to 100 feet, and makes a great first dive with many different species, including barracuda, sea turtles, eels, lobsters, schools of Creole wrasse, and sometimes reef sharks.
The diving in Nevis is also excellent, although there are understandably fewer sites on this much smaller island. The Aquarium site on the windward side of the island represents another anomaly of St Kitts and Nevis scuba dive sites that makes the waters here so varied. The islands face the Atlantic (windward, rougher waters) and the Caribbean (leeward and calmer seas). This means the rougher water at the Aquarium keeps it a nearly virgin site full of fish. It's for experienced divers only who have the stomach for rough surface waters and unpredictable currents below. On the other hand, you have the Vents, located only a short boat ride off popular Pinneys Beach. This site is known for its amazing black coral and unusual thermal water vents up to 100 degrees Fahrenheit. Devils Caverns is located at the far southern tip of the island, and offers caverns and swim-throughs filled with marine life.
In addition to scuba diving, St Kitts snorkeling is also excellent, and can be done from boats on excursions around the islands. However, the most accessible St Kitts snorkeling is available to almost everyone from the islands' many beautiful beaches. There is a very good and very easy reef dive site not far off Friars Bay that is perfect for visitors who have had only the minimum of lessons. Because the reef is so close to the shore, the St Kitts snorkeling is very good off this extremely popular beach.
One of the most popular St Kitts diving sites is the wreck of the River Taw, an inter-island cargo ship intentionally scuttled in 1981 and located just off the harbor at Basseterre. This is an easy dive that almost anyone can navigate, and it's one of the only places where the fish are fed, so they are accustomed to divers and can be seen quite close. The passages and holes in the wreck are home to stingrays, octopus, turtles, lobsters, and numerous fish.
Most of the St Kitts diving is available on the windward (Caribbean) side. The Aquarium on Nevis is one exception. One of the few other exceptions is Booby Island found in the body of water between the two islands that is called the Narrows. Tiny Booby Island is one of the few places here where diving is possible, and it is possible to have night dives. The island is quite near Majors Bay and Cockleshell Bay, where there are operators who can take you out here. It's also accessible by boat from Charlestown on Nevis.
Many of the St Kitts and Nevis scuba dive sites are close enough to Port Zante in Basseterre that they are popular as shore excursions for passengers on the largest ships on Caribbean cruises. These ships dock here generally only for one or two nights. But it is possible to do a couple of tours a day, including a half or full-day dive excursion.