diving your sanctuaries

Channel Islands National Marine Sanctuary

From wildly colored inch-long nudibranchs to robust giant sea bass, an amazing variety of marine life awaits those willing to adapt to cold-water diving in the Channel Islands National Marine Sanctuary. Wetsuits of 6-7mm complete with hoods and gloves or drysuits are the typical choices of most divers here. Many leave the transportation across the Santa Barbara Channel to the sturdy fleet of charter boats that average 60 to 80 feet in length.

Diving is typically conducted in buddy pairs, as lack of visibility in the shady, towering kelp forest can make it difficult to tour the reef in larger groups. Each island in the Sanctuary has its own unique look, both above and underwater. The two smallest islands, Santa Barbara and Anacapa, offer some of the clearest water for diving. Their assemblage of marine life is influenced by the warmer temperate current, and many species like the moray, giant sea bass, garibaldi, California sheephead, and spanish shawl nudibranch prefer this temperature range.

As underwater photography has grown in popularity, so has the popularity of diving in the marine reserve that borders the north shore of East Anacapa. Here, the water from the shore out to 10 fathoms (60 feet) has been a fully protected "no take" zone for more than two decades. The reserve contains a kelp forest full of flora and fauna, perfect for photographers and divers interested observing marine life.

The largest of the Channel Islands, Santa Cruz, is in a transition zone where the warmer southern current and cooler northern current commingle. Diving around Santa Cruz, you might encounter animals from the warmer temperate waters swimming side by side with animals from the cooler zone. Santa Cruz is geologically diverse, and this is also reflected in the structure of the varying marine habitats around the island.

On the north shore, there are some steep walls and dramatic rocky reefs, as well as sand and mudflats. Many reefs along the eastern and southern sides of the island resemble staircases, evidence of the uplifting forces that helped create the island. The layered structure of this type of reef provides excellent habitat for filter feeding animals such as sponges, anemones, and cup corals, as well as hiding places for cryptic fish like sculpin, greenlings, and juvenile rockfish.

Both Santa Rosa and San Miguel islands are exposed to the predominant wind and swell from the west. The colder current from the north influences the marine life around these two islands. While a sea thick with krill and other planktonic organisms can reduce visibility for divers, it provides a soup of life for the local marine residents. On the northwest side of Santa Rosa, a favorite destination is the wide, rocky expanse known as Talcott Shoals. Now lacking the thick kelp that once covered the reef, Talcott is still rich with fish and invertebrates. Divers visiting Santa Rosa will still find a nice kelp forest on the south side of the island at Johnson's Lee.

When San Miguel Island is accessible, the diving can be world class. The marine life here resembles what one might find in Monterey Bay National Marine Sanctuary. Bright red vermilion rockfish, large rose anemones, and delicate purple California hydrocoral decorate rocky reefs beneath healthy canopies of giant kelp. A closer look will reveal many small fish and invertebrates inhabiting almost every inch of space. When illuminated with a dive light, the color spectrum is amazing.

-- Kathy deWet-Oleson

Quick Facts


Cordell Bank National Marine Sanctuary

Remote and deep, with strong currents, Cordell Bank does not provide good recreational diving opportunities, but volunteers are welcome to get involved with education and outreach efforts to protect the 526-square-mile sanctuary. Waters around the bank are generally 400 feet deep, but along a few of its ridges and pinnacles this submerged island rises to within 120 feet of the ocean surface. The depth, currents and distance from the mainland have largely kept this fascinating part of the California seafloor a mystery to both scientists and the public. However, with ongoing research and volunteer monitoring, strides are being made in understanding, protecting and teaching the public about this special place.

Quick Facts

  • Cordell Bank is one of the richest upwelling sites in the Pacific Ocean.
  • More species of albatross have been identified here than anywhere else in the northern hemisphere.
  • Throughout the year, the sanctuary is host to five endangered or threatened species: the Stellar sea lion, humpback whale, blue whale, brown pelican and short-tailed albatross.
  • Beach Watch (volunteer)
  • SEALS (volunteer)
  • Sanctuary Regulations
  • Current Weather
  • Shipwreck Database


Fagatele Bay National Marine Sanctuary in American Samoa

Coral reefs in American Samoa contain a vast array of species. The 275 species of stony coral create the foundation of the reef and are joined by 1,200 species of other invertebrates, 950 species of fish, 11 species of marine mammals, and four species of sea turtles. The sanctuary features humpback whales, octopus, anemones, crabs, blacktip reef sharks, parrotfish and hawksbill turtles.

Experienced divers can take advantage of the abundant variety of shore dives accessible along Tutuila's coasts. Dramatic plunging walls can be accessed along the south shore of Tutuila while meandering reef sculptures characterize the north shore of the island. It should be noted that divers are still much of a novelty to village children in American Samoa so please do not be offended if the village children gather to watch you climb into the water.

In the past, many dive sites in American Samoa have been inaccessible to recreational divers in the past. That will change thanks to a pair of recent developments. In fall 2012, the first dive shop in American Samoa is scheduled to open. The shop will offer instruction, rentals, and dive tours from shore and by boat to more remote locations. In addition, the first hyperbaric chamber was installed at the LBJ Tropical Medical Center. The chamber can be used to treat divers who suffer from the bends.

Quick Facts

  • Visibility is dependent on weather conditions, swell, and proximity to shore. Generally visibility is best during the dry season (May-September). Most dive sites around Tutuila have an average visibility of 30 feet but many sites can have an average visibility of 60 feet or more.
  • Water temperatures in American Samoa are consistently warm and range from the low 80s in the cool season (May-September) to the high 80s in the warm season (November to March). Warm sea temperatures mean that a rash vest and board shorts should be fine for diving at any time of year.
  • Sanctuary staff works closely with the local government to incorporate aspects of traditional Samoan culture into management of the sanctuary. Divers are encouraged to respect local dress and protocol when visiting the Sanctuary.
  • Sanctuary Regulations
  • Current Weather


Florida Keys National Marine Sanctuary

An international dive destination, Florida Keys National Marine Sanctuary is home to one of the most diverse underwater assemblages of plants and animals in North America. Protected in the sanctuary are fringing mangroves, seagrass meadows, hardbottom communities and shipwrecks like the City of Washington, Benwood, Bibb and Duane, which are only a few of the pre-colonial and modern maritime highlights along the sanctuary’s Shipwreck Trail.

Each of the habitats in the Florida Keys provides a home to a dazzling array of marine life. Corals such as elkhorn, staghorn, billiard and brain abound, as do a variety of other residents including goatfish, parrotfish, lobster and nurse sharks. Water temperatures range in the mid-80s in summer and low 70s in winter. Visibility can vary greatly according to weather conditions and other factors, but is typically in the 40- to 60-foot range. When the Gulf Stream moves close to the reefs, visibility can exceed 100 feet.

Quick Facts


Flower Garden Banks National Marine Sanctuary

About 100 miles off the coasts of Texas and Louisiana, a trio of underwater gardens emerge from the depths of the Gulf of Mexico. These fertile coral reefs — the northernmost of their kind in the continental U.S. — serve as regional reservoirs of shallow water, bringing together in one spot a dense and diverse mix of marine life. The salt domes of Flower Garden Banks and Stetson Bank provide home to corals, sponges and colorful Caribbean reef fishes.

Even big marine life frequents the sanctuary, which hosts visitors such as manta rays, loggerhead turtles, hammerhead sharks and occasionally massive whale sharks. Visibility can vary but generally stays between 75 – 150 feet, providing for great dives even on the worst day. Similarly, temperatures range from the mid-60s in the winter well into the 80s during summer. All of these factors combine to make Flower Garden Banks National Marine Sanctuary a premier diving destination.

Quick Facts


Gray’s Reef National Marine Sanctuary

The 23-square-mile Gray’s Reef sanctuary is located 20 miles east of Sapelo Island, Georgia. One of the largest nearshore limestone reefs in the southeastern U.S., the sanctuary lies in waters 50 to 70 feet deep, optimal for the colonization of a live-bottom community. An array of marine invertebrates such as sponges and soft corals flourishes at Gray’s Reef, attracting a rich diversity of fish species including snapper, grouper and amberjack.

Larger marine life includes animals like the Loggerhead sea turtle and marine mammals such as Atlantic spotted dolphin and the endangered northern right whale. In fact, the sanctuary lies just north of the calving grounds for this endangered whale, and in 1986, the United Nations designated Gray's Reef an International Biosphere Reserve, providing global testimony to the importance of this area for marine life. Visibility is usually between 15 - 45 feet, with temperatures ranging from a cool 50 degrees in winter to 85 in summer. Because of the seasonal changes in temperature at this site it is not uncommon to see subtropical species of fish in the summer and temperate species in the winter; diving Gray's Reef is never the same place twice.

Quick Facts


Gulf of the Farallones National Marine Sanctuary

Gulf of the Farallones National Marine Sanctuary, just outside San Francisco's Golden Gate, boasts some of the most beautiful, dynamically productive and awe-inspiring marine waters in the world, supporting lively humpbacks and majestic blue whales, soaring albatross, and the world's largest breeding colony of seabirds in the contiguous United States. These features, combined with vast tracts of sandy beach stretching for miles north and south of the Gate, offer great wildlife viewing and surfing. However, this stretch of coastline lacks coves that make for sheltered dive conditions.

Also, the sanctuary's strong currents, cold murky water, and large white shark population give many divers pause. These conditions present safety challenges for cage-free diving, even in nearshore mainland waters, since "whites" may hug the coast before ranging offshore to visit the waters around the Farallon Islands - their favorite spot to dine on young elephant seals. White sharks have been seen here in every month of the year, but their presence spikes in the fall, coinciding with the young seals' visit. An industry has grown around cage diving at the islands.

The State of California's system of Marine Protected Areas has instituted special closures around some islands, headlands and promontories especially rich in wildlife, but vulnerable to human impacts. Check access regulations for these areas and a map of these sites before heading out.

In order to prevent disturbance to this very important white shark population the Farallones sanctuary recently enacted legislation banning their attraction or approach, and established the White Shark Stewardship Program.


Hawaiian Islands Humpback Whale National Marine Sanctuary

One of the world’s most important humpback whale habitats lies within the 1,370 square miles of ocean surrounding the main Hawaiian Islands managed by the Hawaiian Islands Humpback Whale National Marine Sanctuary. Scientists estimate that two-thirds of the entire North Pacific humpback whale population migrates to these warm, shallow Hawaiian waters to breed, calve and nurse their young.

In addition to the humpbacks, the sanctuary is host to an impressive mix of large marine animals such as the Hawaiian monk seal, dolphin, manta ray, green sea turtle and whitetip shark. A diverse array of topographic features such as lava tubes, caverns and coral reefs top off this unique diving locale, making for some of the best U.S. diving west of California. Average temperatures range from 70 to 80 degrees with visibility between 75 – 100 feet.


Quick Facts


Monitor National Marine Sanctuary

Designated in 1975, the one-square-mile Monitor National Marine Sanctuary was the nation's first marine sanctuary. It is also the only one dedicated to the preservation of a single cultural treasure, the wreck of the famed Civil War ironclad, USS Monitor. The Monitor is recognized worldwide for its significance as a vessel that revolutionized 19th-century naval warfare technology and for its famous 1862 battle against the Confederate warship, CSS Virginia in Hampton Roads, Va.. Sinking less than a year after that historic battle in a storm off Cape Hatteras, N.C., the Monitor remained lost beneath the waves for more than 100 years until its wreck was located in 1973.

Due to the great depth and unpredictable currents, the Monitor is inaccessible to most divers, although it remains popular with technical divers who use the necessary breathing gas mixes and procedures. For everyone else, the USS Monitor Center, which opened in March 2007 at The Mariners' Museum in Newport News, Va., features a stunning collection of exhibits and information on the history of the vessel. Highlights from the center include the Monitor's iconic rotating gun turret and cannons, which were recovered in August 2002, and a full-size replica of the Monitor herself.

Quick Facts

  • The Monitor wreck rests 230 feet below surface off the coast of Cape Hatteras, N.C.
  • Designated in 1975, the Monitor site was the first national marine sanctuary.
  • The Monitor was the U.S. Navy’s first ironclad vessel.
  • Sanctuary Regulations
  • Current Weather


Monterey Bay National Marine Sanctuary

The largest of the 13 sanctuaries, Monterey Bay National Marine Sanctuary contains many diverse biological communities, from rugged rocky shores to towering giant kelp forests to the great depths of one of North America’s deepest underwater canyons. These habitats provide home to an abundance of marine life including rockfish, swordfish, squid, California sea lions, sea otters and several species of sharks and rays, as well as 27 rare and endangered species like the huge blue whale.

With multiple entry points such as Monterey Bay, Carmel Bay and Point Lobos, the Monterey Bay sanctuary provides some of the best diving opportunities on the West Coast. It is among the cooler sanctuary dive destinations, with average water temperatures in the mid-50s year-round, and dropping to the 40s at deeper sites. Visibility averages 20 to 30 feet, reaching up to 60 feet in fall, providing excellent conditions in which to experience the rich marine life that lives in these waters.

Quick Facts


Olympic Coast National Marine Sanctuary

Olympic Coast National Marine Sanctuary off the outer Washington coast is the site of rich upwelling currents, making it one of the most productive marine ecosystems on the planet. Within the 3,189 square miles of sanctuary waters are a host of impressive diving habitats including more than 150 documented shipwrecks (most at depths beyond a diver's reach), rocky reefs, kelp forests, and sea stacks that are home to abundant marine life, from gray and humpback whales to otters, salmon and rockfish.

On a typical dive, common sights include numerous species of colorful and varied marine invertebrates, rockfish, ling cod, greenling, wolf eels and the great Pacific octopus between canopy kelp and lush understory algae. Lucky divers may observe pinnipeds, sea otters and diving seabirds foraging for food. With average temperatures in the 50s and visibility ranging from 15 to 60 feet, the sanctuary boasts some of the best cold-water diving in the U.S. September offers the most consistent weather, and diminished upwelling during that time of year provides better visibility. Advanced skills and extensive experience is required to deal with the challenging conditions of this high energy environment with swell, strong currents, open water, and limited visibility.

Quick Facts


Papahānaumokuākea Marine National Monument

Papahānaumokuākea Marine National Monument and World Heritage Site, the largest marine protected area in the United States and one of the largest in the world, encompasses nearly 140,000 square miles of the Pacific Ocean around the Northwestern Hawaiian Islands - an area larger than all of America's national parks combined. The extensive coral reefs found within the monument are home to more than 7,000 marine species, one quarter of which - like the endangered Hawaiian monk seal - are found nowhere else on Earth.

To preserve the nearly pristine ecosystems of the Northwestern Hawaiian Islands, general access is only granted by permit, while Midway Atoll allows limited recreational access; find out more here. While we must protect this underwater treasure by not interfering with it, there are many ways to experience its wonders from afar. At the Mokupāpapa Discovery Center, the monument's 4,000-square-foot facility in Hilo, visitors can experience a "virtual dive" surrounding the Northwestern Hawaiian Islands.

Quick Facts

  • The Northwestern Hawaiian Islands have some of the healthiest and most extensive coral reefs in the United States.
  • The monument covers 137,797 square miles, making it the largest conservation area in the United States and one of the largest marine conservation areas in the world.
  • Papahānaumokuākea's waters contain numerous historical and cultural artifacts, and the area has great cultural significance to Native Hawaiians.
  • Monument Regulations
  • FAQs


Stellwagen Bank National Marine Sanctuary

While many of New England's most popular dive spots are close to shore, some excellent diving can be found further afield. Stellwagen Bank National Marine Sanctuary's position between Cape Ann and Cape Cod offers divers a chance to explore different environments at the mouth of Massachusetts Bay, where strong currents and exposed waters create challenging dive conditions.

Fifteen percent of the sanctuary, approximately 126 square miles of seafloor, is shallower than 130 feet at low tide. Much of this area lies atop Stellwagen Bank in the middle of the sanctuary. Other areas that fall within the recreational diving limits are portions of Jeffreys Ledge and Sanctuary Hill along the sanctuary's northern border. Most dive sites are in the 100-foot depth range.

The sanctuary is home to varied marine life in greater numbers than what is seen inshore. What you will see depends upon the environment you visit. In the sand and gravel areas on top of Stellwagen Bank you may encounter sand lance schools and monkfish, while the boulders on Jeffreys Ledge hide Acadian redfish and Atlantic wolffish. At nearly every location you will encounter large sponges and anemones encrusting rocks or shipwreck structure. You are also likely to see sculpins, flounders, cunner, skates, and cod on most dives. Schools of dogfish or pollock make dives particularly exciting.

Four shipwrecks sunk on Stellwagen Bank give divers the opportunity to explore sunken relics of the area's fishing fleet. Marine life is particularly abundant on the shipwrecks where structure and crevices create oases of biodiversity on otherwise sandy seafloor. In partnership with local dive charters, the sanctuary has begun installing subsurface mooring on the shipwrecks to facilitate diver visitation.

Highly variable weather events, however, do not always favor small craft, and diving can be similarly hazardous. With this in mind, dives should only be considered by experienced divers with advanced certification, along with capable surface support knowledgeable of the area.

Quick Facts

  • Stellwagen Bank was formed by glacial activity during the last ice age.
  • Nutrient rich waters rising to the surface make the sanctuary a prime feeding ground for humpback whales, fin whales, minke whales and white-sided dolphins.
  • Enjoy watching these beautiful animals during your surface interval, but do not intentionally enter the water to dive with a marine mammal.
  • Divers may see schools of bluefin tuna, Atlantic cod, pollock, and spiny dogfish while winter flounder, sea scallops and northern lobster hide amongst rocks and sand ripples on the seafloor.
  • Divers should plan to dive during slack tide periods, which can be judged by subtracting 30 minutes from slack tide at Boston Light. Choose a day with less tidal exchange for the longest slack tide window.
  • Dive boat should fly both the red and white 'diver down' flag and the blue and white Alpha flag to warn other vessels when divers are below.
  • Late summer offers the best sanctuary diving conditions with warm surface water, good tides, and periods of calm seas.
  • Even in the middle of summer, water temperatures are around 45 degrees Fahrenheit at the seafloor.
  • Visibility is best during the winter months; however, summer visibility is rarely less than 30 feet.
  • Current Weather Buoy Information
  • Stellwagen Bank Sanctuary Dive Sites


Thunder Bay National Marine Sanctuary

Created in 2000, Thunder Bay National Marine Sanctuary protects one of America's best-preserved and nationally significant collections of shipwrecks. From Native American dugout canoes to wooden sailing craft and steel freighters, thousands of ships have made millions of voyages across the Great Lakes. The last 150 years have been particularly explosive transforming the region into one of the world's busiest waterways.

Yet with extraordinary growth comes adversity. Over 200 pioneer steamboats, majestic schooners and huge steel freighters wrecked near Thunder Bay alone. Due to Lake Huron's cold freshwater, many of these sites remain virtually unchanged. With masts still standing, deck hardware in place, and the crews' personal possessions often surviving, sites located in deeper waters are true time capsules.

Other shipwrecks lay well preserved, but broken up in shallower waters. The density of the wreck sites allows divers to experience a 19th century wooden schooner on one dive and a 20th century steel freighter the next. Through research, education and resource protection, the sanctuary works hard to ensure that the Great Lakes maritime heritage is accessible - whether underwater, on the water or even virtually!

Visibility is generally excellent, with many days well over 100 feet. The maximum surface temperature by August reaches the mid-70s, though depths greater than 45 feet stay in the mid-50s, and drop to the 30s in technical diving ranges. Dive season starts around Memorial Day and extends through mid-October.

Quick Facts

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Revised June 21, 2013 by Sanctuaries Web Team | Contact Us | Web Site Owner: National Ocean Service
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