Looking for great diving here in the good ol’ US-of-A? Then National Parks should be on your radar! Everyone can see Old Faithful and the Redwoods, but only divers can explore millions of acres of submerged parkland.

Glacier National Park

Location

The park straddles the Canada-U.S. border between Montana and Alberta; both Lake McDonald and Saint Mary Lake are open to divers.

When to Go

The park is open year-round, though facilities can close in severe winter weather. April to November is best for diving, with midsummer water temps ranging from 60 degrees at the surface down to about 40 degrees at 100 feet.

Dive Shop

Flathead Scuba is a dive shop about half-an-hour from the park’s main dive site, Lake McDonald.

Experience

Intermediate to advanced skills; must have experience in altitude and frigid-water diving—Lake McDonald is more than 3,100 feet above sea level. The cold water temperatures generally provide good viz.

Stay

There are campgrounds throughout the park, with three (Fish Creek, Apgar, and Sprague Creek) near Lake McDonald that cost between $20 to $23 a night.

Discover

Divers can explore underwater trees about 50-feet below the north end Lake McDonald. The south end of the lake, easily accessible from the Apgar visitor center, offers old docks, tools and a small boat on the sound end. A shallow wreck known as Fish Creek Bay Wreck rests at max ten feet deep in Fish Creek, near the southern end of Lake McDonald.

Get ready to dive Glacier National Park with PADI’s Altitude Diver and Drysuit Diver courses.

Channel Islands National Park

Location

The park covers five islands off the southern California coast by Santa Barbara: Anacapa, Santa Cruz, San Miguel, Santa Barbara and Santa Rosa.

When to Go

Channel Islands National Park is open year-round; many consider the fall to be ideal because temperatures reach 70 degrees F and visibility averages 100 feet.

Dive Shop

Book a Channel Islands liveaboard with Horizon Charters, or a day excursion with shops like Cal Boat Diving or Channel Islands Dive Adventures.

Experience

Due to windy conditions on Santa Rosa and San Miguel, currents can be unpredictably strong, so divers need to be experienced and properly trained, conditioned and equipped. ­Wetsuits and hoods are recommended during colder months, when the water temperature ranges from 55 to 70 degrees F.

Stay

There is one campground on each of the five islands. Reservations are required and cost $15 a night. Conditions are rustic—fires are not permitted, campers must take their trash with them off the island, and Santa Rosa and Santa Cruz Islands are the only two sites that have water.

Discover

Divers can explore kelp forests, coves, caves and more throughout the islands. Painted Cave stretches nearly 1,300 feet long and 100 feet wide along the northwest coastline of Santa Cruz. Dive Landing Cove off Santa Barbara to find sea stars, spiny sea ­urchins, orange garibaldi, playful sea lions and harbor seals.

Dry Tortugas National Park

Location

Spanning 100 square miles and seven small islands, this remote national park is roughly 70 miles from Key West and is accessible only via boat or seaplane.

When To Go

Open year-round, including holidays; for best conditions, go between May and September to avoid thunderstorms. Water temperatures range from 87 degrees F in summer to 68 degrees F in winter, and visibility ranges from 40 to 100 feet depending on the conditions.

Dive shop

Adventure Watersport Charters, based in Key West, offers diving liveaboard charters from two days and two nights to four days and four nights.

Experience

The Dry Tortugas offers dive sites suited for all levels. The inner (3- to 30-feet deep) and outer (35- to 80-feet deep) reefs teem with coral and marine life — and have excellent natural light, good for underwater photographers.

Stay

Camping on Garden Key in Dry Tortugas National Park costs $15 for an individual campground, which can accommodate up to six people, or $30 for a group campground. Reservations are not required for individual campsites. Plan ahead when it comes to transportation—the commercial ferry to and from Garden Key only takes ten campers each way per day. Private boats are permitted, but can only anchor in sandy or rocky areas within one nautical mile of the Fort Jefferson Harbor Light.

Discover

Divers can encounter sea turtles, nurse and bull sharks, eels, friendly goliath grouper, and an abundance of lobsters. It’s also a wreck-diving hot spot, from the iconic—and rec-friendly—Windjammer to tec-wrecks Araby Maid and M/S Rhein Hamburg.

Kenai Fjords National Park

Location

This park in Alaska covers more than 1,000 square miles.

When To Go

May through August.

Dive Shop

Dive Alaska is a full-service dive center based in Anchorage with boat charters into Resurrection Bay.

Experience

This site is for intermediate to advanced divers ready to handle visibility that can swing from poor to excellent. Additional challenges include frigid ocean currents and no local diving businesses, but the rewards include stunning marine life.

According to the National Park Service (NPS), this park is logistically “extremely challenging” for divers. The closest dive shops—including sites for air fills—are in Anchorage, over 120 miles away. Divers are responsible for getting all of their gear to the park, “which needs to include a compressor,” according to NPS. Charter boats in the nearby town of Seward can take you diving in the park.

Stay

Exit Glacier, a campground in the park, has 12 spots given away at a first come, first serve basis. It often fills up in July and August. Nearby Chugach National Forest also has several campsites, which range from $10 for a single site to $150 for a group site.

Discover

Get ready for big sea life encounters! Sea lions, orcas, grey or humpback whales, sea otters and sea bass all rove the fjord. NPS even claims there is halibut “the size of a barn door” romping around.

Acadia National Park

Location

The Maine park sprawls across portions of several islands scattered just off the coast, including Mount Desert Island and Isle Au Haut.

When To Go

Mid-July is the prime time.

Dive Shop

Johnson's Sporting Goods-Rockland, about two hours away, is among the closest dive shops.

Experience

Intermediate to advanced divers will find limited shore diving and copious boat diving in cold water conditions. Divers will have to contend with tidal currents and poor to moderate visibility ranging from 10 to 30 feet. NPS recommends a portable compressor for divers leaving Mount Desert Island.

Stay

There are three campgrounds across the park islands, and five lean-tos on Isle au Haut. Prices range from $22 for an individual tent site to $60 for a group site.

Discover

Try a shore dive in the Somes Sound, the east coast’s only fjord, or scan for famous Maine lobster at sites like the Seawall and Otter Point.

Yellowstone National Park

Location

Largely in Wyoming, parts of this park stretch into Montana and Idaho.

When To Go

July and August.

Dive Shop

Based in Jackson, Teton Aquatic has a 42-year history of diving lakes and rivers throughout the region.

Experience

Diving in Yellowstone is for intermediate to advanced divers trained for altitude diving and cold water; visibility is poor to moderate, ranging from 10 to 30 feet. The main dive site, Yellowstone Lake, is among the world’s largest altitude lake dives, covering 125 square miles more than 7,700 feet above sea level. Shore dives are the norm.

Stay

There are 12 campgrounds in the park, five of which require reservations ahead of time. Tent campsites range from $15 to $32 a night. Grant Village and Bridge Bay campgrounds are the closest sites to Yellowstone Lake.

Discover

Thermal columns fizz visibly upward in Mary Bay at the northeastern corner of Yellowstone Lake, giving divers the chance to hover in a steady stream of warm bubbles that cause visual distortions. The E. C. Waters, a 125-foot steamer, sits just eight feet below the surface of the lake.

Exercise caution diving in the West Thumb Geyser Basin—NPS warns the thermal vents have uneven water temperatures, water can be cold in one section but dangerously hot nearby.

Get ready to dive Yellowstone National Park with PADI’s Altitude Diver and Drysuit Diver courses.

Olympic National Park

Location

The shore of northwestern Washington.

When To Go

June to October.

Dive Shop

Port Angeles-based Strait Scuba is a full-service dive center leading guided dive excursions throughout the North Olympic Peninsula coast.

Experience

Intermediate to advanced divers should stay vigilant for tidal currents, surge, rocks and loose logs. Water will be cold whether diving in the ocean or inland. Most dives begin from shore.

Stay

Pick from 14 campgrounds within the park, only three of which accept summer reservations. The rest are walk-in only. Prices range from $15 to $24 a night, sites are limited to eight people.

Discover

Skim along with sizable white-and pink-plumed anemones in Hood Canal, a 70-mile long inland extension of the Pacific Ocean. For freshwater diving, head to Lake Crescent—you can find a barge at 25 feet in pristine water that offers visibility up to 150 feet. Just outside the national park is Salt Creek State Park, where divers can explore a wreck called the Diamond Knot sits in 80- to 140-feet of water or a kelp bed teaming with marine life.

DIVE DEEPER: For more information about diving in national parks, head to NPS.gov/Submerged.

Related:

• The 50 Best Dive Sites in the U.S.A.
• Why We Love Diving in the U.S.A.
• Drive and Dive: Straits of Mackinac