Scuba Diving North Mariana Islands

The Commonwealth of the Northern Mariana Islands (CNMI) consists of 15 islands in the Micronesian region of the western Pacific Ocean.  North of Guam, these islands are known for their beautiful beaches, perfect aquamarine waters, and the laid-back, unhurried lifestyle of its residents.  Only the islands of Saipan, Rota, and Tinian are permanently inhabited and the diving is considered some of the best in the world.  There are beautiful coral reefs dotted with tropical fish; the sunken ships and other relics of World War II; and stunning caverns and caves perfect for underwater photography.  The diving is diverse, but always has warm waters and great visibility.  Ranging over 400 nautical miles, the southern limestone islands are surrounded by fringing coral reefs and the northern islands are volcanic with three still actively volcanic. 

There are three paved airport runways in the CNMI: Saipan International Airport (SPN), Rota International Airport (ROP), and Tinian International Airport (TIQ).  Most flights go into Saipan from Guam, Seoul, and Tokyo.  A few flights from Japan fly directly to Rota and Tinian, but most travelers fly into Saipan first and take one of several daily flights to the other two islands.  There is a ferryboat operated by the Tinian Dynasty Hotel and Casino that goes between Saipan and Tinian.  Otherwise it is necessary to fly between islands or make private arrangements to get there by boat. 

Tinian is a 45-minute boat ride from Saipan, so some operators on Saipan may dive the sites on Tinian.  Otherwise the best way to dive all three islands is to go to each island and dive with a shop on that specific island.  There are no commercial operators who dive the more northern islands, although it’s likely to be great diving if private arrangements can be made to take a boat there.

The CNMI has a tropical marine climate that is hot and humid year round with northeastern trade winds creating a comfortable sea breeze.  There is little temperature fluctuation throughout the year, but typhoon season is July through November and this time of year gets more rain.  The air temperature averages 83F and water temperature averages 82F year round. 

The official languages are English, Chamorro, and Carolinian, but as the CNMI is a very popular tourism destination for Japan, Japanese is widely spoken in hotels, restaurants, and dive shops.  It’s a good idea to ask in advance what languages dive shops teach or lead dives in because several shops only speak Japanese. 

The CNMI are very remote and it can be difficult to purchase everyday items a diver may need.  Be sure to bring plenty of extra batteries for cameras and flashlights, camera memory cards, and chargers, as you may not be able to buy them there. 

The Northern Marianas has plenty of beautiful reef diving for both beginner and advanced divers.  There are both shallow and deep reef dives and several spectacular caverns and caves.  Playing a role in WWII, the CNMI has several sunken ships and other WWII relics that can be explored underwater.

Saipan

Saipan’s most popular dive site is The Grotto, a collapsed limestone cavern with awesome light beams that penetrate through holes in the cavern walls.  It is also often voted one of the best dive sites in the world and an underwater photographer dream dive site.  Entry is from land after climbing 112 steps through the top of the cavern, and the walls are covered in coral and macro marine life.  There are three underwater exits to open ocean, and divers often see turtles, schools of barracuda, and other fish.

The Chinsen Maru is an Imperial Japanese Navy freighter that sank in 1944 after being torpedoed during WWII.  The shallow wreck sits on the bottom at only 35ft and part of it breaks the surface making it an easy wreck to explore and great for newer divers.  Octopuses are commonly found on this wreck, jacks frequent the area, and white tip sharks are usually underneath the ship.

Also on Saipand, Lao Lao Bay is a great shore dive with fantastic coral formations and lots of turtles. Eagle Ray City is a great spot to see eagle rays, sometimes up to 30 at a time.  Ice Cream is a popular dive site and is named after ice cream cone shaped corals that are colorful and host even more colorful fish life. 

Tinian

Tinian Grotto is a fantastic cavern dive accessible from the top with two exits near the bottom that continue out along a wall covered in marine life.  Two Coral Heads is a site, which, as expected, has two large corals heads next to each other.  These healthy coral heads support many reef fish species such as grouper, parrotfish, butterflyfish, and angelfish.  A popular WWII artifact area, Dump Cove, has planes, tanks, jeeps, and ammunition from WWII and turtles frequent the area.  Tinian’s best wall dive (and probably the best wall dive in the CNMI) is Fleming, which drops past 200ft and has perfect visibility. 

Rota

Rota has several WWII wrecks including the Shoun Maru, a Japanese ship which was sank in 1944 from being torpedoed.  It sits in the sand at 110ft, with the deck at 65ft.  Visibility is usually very good and there is plenty of fish life around the wreck.  There are also bikes, bathtubs, and tanks inside.

Rota’s most popular dive is Senhanon Cave, which is a cavern accessed at 40ft.  Inside there are schools of fish and lobster and underwater photographers love the penetration light beams. Other popular dive sites include Coral Garden, a shallow reef, which is a favorite spot for octopus, turtles, and the occasional shark.  Slightly deeper, Table Top is two seamounts with lots of life. The dive is from 90ft to 15ft. 

Diving in the CMNI can be done in a rash guard or shorty wetsuit, or a 3mm at most. 

The Northern Mariana Islands are very remote, and dive shops on the islands seem to come and go depending on how much tourism is coming into the islands.  As less people are traveling to the CNMI, shops are disappearing as well.  With the majority of tourism coming from Japan, several dive shops only conduct classes and guided dives in Japanese, so it’s a good idea to contact shops in advance to be sure they can accommodate your needs.  There is a Northern Mariana Diving Operators Association (NMDOA) to which reputable dive shops belong.

One of the most popular dive shops in Saipan is Mariana Sports Club.  They offer PADI certification courses, daily guided boat dives, shore dives, rental gear, and provide pick-ups from Saipan hotels.  They also keep a blog almost daily of each day's diving, what they saw, conditions, class info, videos, and photos.  They conduct courses and guided dives in Japanese and if they have multilingual instructors, will provide other languages as well.    

Another favorite is Aqua Marine, which offers PADI certifications, daily-guided dives both from shore and from boats, and other water sport activities like jet skis.  S2 Club teaches PADI courses in Japanese, offers guided dives, and has rental gear.  Also on Saipan, WonderSea Saipan Inc. and Seashore offer PADI courses from discover scuba through instructor. Both have a full retail shop and rental gear available, and offer guided shore and boat dives. 

On Tinian, Crow’s Nests, offers boat diving, beach diving, discover scuba diving and other PADI courses. On Rota, Dive Rota can arrange guided shore and boat dives to Rota’s most popular dive sites.  They can also help with flight and accommodations on Rota. It’s probably best to bring your own gear, especially all your favorite gadgets, as it’s difficult to get things to the CMNI, particularly on Rota and Tinian.