Training to go ever deeper can seem like a dare — a challenge driven by ego, not purpose. But these wrecks and their stories, artifacts, and bygone ­beauty ­compel us to redraw our comfort zones. To train to become proficient with a new gas mix, or perhaps a rebreather. To work until we are mentally and ­physically ready for tasks at depth. Further still, those who penetrate ­expose themselves to another set of challenges, and another set of rewards. The ­result of any such training, and the subsequent successful wreck dive, is not only the sense of accomplishment when beholding your quarry, but also of ­becoming part of that wreck’s next chapter. Exploring these wrecks ­is guaranteed to test your mettle, skill and discipline, to entice you to go deeper. These are the dives that will make you say, “challenge accepted.”

BONUS: The 25 Best U.S. Wreck Dives

Wrecks in the U.S. and Canada

U.S.S. MONITOR
Cape Hatteras, North Carolina, USA
The permit-only nature of the site, the depth and the Gulf Stream’s force — sometimes up to 2 and a half knots — limit the number of tec divers who see this Civil War iron-hulled steamship. In 2015, the charter vessel Under Pressure took one day trip where just two tec divers dropped onto the wreck, 17 miles from shore. Most memorable is the Monitor’s small size. Says Captain J.T. Barker, “These guys were waging war in a ship I wouldn’t go to sea in.” Note that NOAA has recovered the turret, prop and engine, leaving mainly the hull. Length Overall: 179 feet
Depth: 240 feet Bonus: See the Top 10 North Carolina Wreck Dives

H.M.C.S. YUKON
San Diego, California

This Wreck Alley favorite provides an ideal training grounds for those looking to strengthen penetration skills; the 2000 purpose-sunk Mackenzie-class destroyer, on its port side, has exit points cut every 10 feet or so. Save for the boiler room, six decks’ worth of spaces, from the engine room to restrooms with rows of toilets, can be explored.
Length Overall: 366 feet
Depth: 100 feet
Bonus: Burma Road, an uninterrupted route spanning bow to stern on deck three, is too far for most recreational divers to finish with one tank. Find a weekend itinerary for San Diego scuba diving here.

U.S.S. ORISKANY
Pensacola, Florida

For recreational divers, the decking island at 84 feet is the main attraction of this aircraft carrier intentionally sunk in 2006; its smokestack and catwalks remain intact. For technical divers, the thrills start at 145 feet with the flight deck, followed by the hangar bay at 175 feet. For recreational divers, the Florida Panhandle Shipwreck Trail has other wreck dives to offer. Length Overall: 911 feet
Depth: 212 feet
Bonus: Art2Media has a detailed Oriskany dive map here.

QUEEN OF NASSAU
Islamorada, Florida, USA
The Mount Everest of the Keys, this former patrol ship that once served in the Royal Canadian Navy was found in 2001 five miles off Islamorada. The steamer ship remains relatively intact save for slight damage to stern and a collapsed mast. Thanks to the depth and warm-water conditions, the marine life sightings can be mind-blowing, including scalloped hammerheads and sawfish.
Length Overall: 200 feet
Depth: 225 feet

U.S.S. SPIEGEL GROVE
Key Largo, Florida, USA
However much gas you carry, you’ll find a way to use it on this 12-deck landing ship sunk to a depth of 140 feet. With advanced wreck training, you can spend an hour or longer finning in the engine room, pump rooms, living quarters, brig and a galley still holding ovens, sinks and a mess hall. Cleaned before sinking, the ship offers ample ambient light and exit points.
Length Overall: 510 feet
Depth: 134 feet
Bonus: Find Snoopy riding an alligator painted on the floor at 85 feet.

Dive this wreck with:

Sea Dwellers
Ocean Divers
Rainbow Reef

S.S. ANDREA DORIA
Nantucket, Massachusetts, USA

The 1956 collision of this ocean liner with the M.S. Stockholm was one of the most epic maritime disasters ever; now it remains diving’s most infamous wreck, claiming 16 divers’ lives. Originally, the nickname “Mount Everest of diving” referred to the likeness of the wreck’s silt to Himalayan snow, but it’s evolved to reference the site’s challenges, namely depth, current and cold waters, 100 miles from shore. Now, the ship has largely disintegrated, making it anything but a clean dive. Penetration was once as easy as following ship blueprints; now one is better off exploring the top deck and its three swimming pools.
Length Overall: 701 feet
Depth: 250 feet

CORNELIA B. WINDIATE
Alpena, Michigan, USA
The three masts of this 1875-sunk wooden grain schooner still point to the Lake Huron surface. This Thunder Bay National Marine Sanctuary treasure remains a local favorite for the artifacts on board, including the grain cargo and bowsprit.
Length Overall: 138 feet
Depth: 180 feet
Bonus: Penetrate to wind along spiral staircases.

S.S. FLORIDA
Alpena, Michigan, USA
Also in the Thunder Bay National Marine Sanctuary, this wooden freighter, downed in 1897, remains intact, including the gauge panel, ship’s bell, engraved capstan, boilers and so much cargo, including barrels, that the wreck site was once often called a 1800s general store.
Length Overall: 270 feet
Depth: 210 feet
Bonus: Don’t miss the massive crack on the starboard side, evidence of the collision with the steamer George W. Roby.

S.S. CEDARVILLE
Mackinaw City, Michigan, USA
Because this steel freighter starts at a depth of 35 feet, it seems novice friendly — and it largely is, though caution must be exercised when penetrating doors and hatchways. The ship lies within Straits of Mackinac Preserve, broken nearly in half but otherwise well preserved on her starboard side following its 1965 collision.
Length Overall: 588 feet
Depth: 110 feet

U-869
Point Pleasant, New Jersey, USA
It’s hard to imagine the sense of fulfillment wreck expert John Chatterton felt when he uncovered the knife that proved that the U-boat nicknamed “U-Who” was indeed the U-869. In his book Shadow Divers, he details the dives through a ghostly veil of silt shrouding the control room, captain’s quarters and officer’s quarters. He finds evidence including torpedoes lying in storage and china detailed with swastikas and eagles. Now the biggest danger to divers wishing to follow in his fin steps are entanglements; the wreck, though impossible to get lost in, is anything but clean.
Length Overall: 252 feet
Depth: 230 feet

STOLT DAGALI
Point Pleasant, New Jersey, USA
Only the 145-foot stern of this steel-hulled tanker sank after the S.S. Shalom sliced into it in November fog in 1964; the bow was saved thanks to airtight compartments. Now, the stern lies on its starboard side starting at a depth of 65 feet. Mostly lobsters are bagged at the site, although the helm stand was recovered in 2012.
Length Overall: 583 feet
Depth: 130 feet
Bonus: Author and wreck expert John Chatterton favors the site for penetration training thanks to its easily accessible hallways, cabins and storage areas.

R.M.S. EMPRESS OF IRELAND
Sainte-Luce-sur-Mer, Quebec, Canada

Don’t let the 130-foot depth fool you. Start with frigid waters, and add swift and sometimes unpredictable currents in this stretch of the Saint Lawrence River. Then consider that this 1906 ocean liner, nicknamed Canada’s Titanic, holds infinite possibilities for penetration and artifact-spotting. But the vessel, now on its starboard side, is deteriorating and showing signs of collapse; visiting the site with a local guide is highly advisable.
Length Overall: 570 feet
Depth: 130 feet
Bonus: No penetration is required to witness the name on the bow, lifeboats and a 10-ton anchor.

U.S.S. YMS-420, AKA NAKAYA
Vancouver Island, British Columbia, Canada
This former minesweeper is easily accessible: It’s less than a 1,000-foot swim from Porteau Cove Provincial Park to where it starts at a depth of 70 feet. The fragile outer structure has collapsed substantially; railings on the main deck remain, as do bolts jutting from the hull that once held wooden planks.
Length Overall: 136 feet
Depth: 100 feet
Go Now: Ocean Pro Divers

H.M.C.S. SASKATCHEWAN
Vancouver Island, British Columbia, Canada
This Mackenzie-class destroyer ship, which served the Royal Canadian Navy amid threats of atomic bombs, was purpose-sunk in 1997 to a depth starting at 40 feet. Now, divers who cruise the penetration routes leading to the magazine room, supply rooms and beyond will notice the round-edged walls designed for easy scrubbing should a nuclear event have occurred.
Length Overall: 366 feet
Depth: 130 feet
Bonus: The ship’s “Burma Road,” a bow-to-stern swim through, can be undertaken on a scooter.

S.S. GUNILDA
Rossport, Ontario, Canada
The Cousteau Society named this Lake Superior steamship one of the world’s best-preserved wrecks. Built in 1897, the steel-hulled ship was the era’s equivalent of a personal jet, serving the Harkness family in luxury until it hit McGarvey Shoal. Upright, it’s intact, with masts, skylights, rudder, portholes, anchor booms and gold-leafing on the bowsprit and scrollwork.
Length Overall: 195 feet
Depth: 262 feet

Asia and Pacific

U.S.S. PERRY
Angaur island, Palau
The water surrounding this Clemson-class destroyer sunk in 1944 is so clear that the ship is visible from the surface — a boon to its discovery in 2000 by one of the survivors in conjunction with a local dive shop. It lies on its port side, ripped in two thanks to a mine collision. Otherwise, it’s in fairly prime condition: Bow guns, propeller and minesweeping gear remain.
Length Overall: 314 feet
Depth: 240 feet Go Now: Sam's Tours Palau

H.M.S. HERMES
Batticaloa, Sri Lanka

Only when Sri Lanka’s civil war subsided in 2009 was this aircraft carrier open to the diving public, making the wartime wreck relatively unexplored since the 1942 bombing that led to the loss of the ship and 307 lives. Now on its port side, it retains details like bulbs in the emergency lights, gauges and intact glass in the control tower, bow guns still aiming skyward, and anchors.
Length Overall: 600 feet
Depth: 174 feet
Bonus: Shell casings still lie near the bow guns, evidence of the final struggle.
Go Now: Sri Lanka Aggressor

FUJIKAWA MARU
Chuuk Lagoon, Micronesia

For those with the training to access this Japanese Navy passenger-and-cargo ship, the rewards include a hold containing three Zero airplanes; including one with an intact cockpit. Dive guides will steer you toward the harder-to-find treasures, including china, a medicine kit and other WWII artifacts. The site is also home to the much-photographed air compressor nicknamed R2D2. Those traversing the outside can appreciate the armament of six-inch guns and the superstructure at 70 feet.
Length Overall: 435 feet
Depth: 120 feet

S.S. SAN FRANCISCO MARU
Chuuk Lagoon, Micronesia

Treat the San Francisco with respect not only for her depth but also for the fact that this freighter is a war grave still containing bodies. It’s a tec community favorite for the four cargo holds: The first contains aircraft bombs, crates of artillery shells, mines and cable spools. Number two shelters two tanker trucks and a flatbed truck. Toward the stern, deck three contains another truck, and deck four protects torpedo warheads, depth charges, mines, crates of ammunition and the aforementioned casualties.
Length Overall: 385 feet
Depth: 206 feet

Europe, Mediterranean and Exotic

S.S. MAIDAN
Marsa Alam, Egypt
This 1912 steamer, a troop transport vessel in World War I, wasn’t on the dive map until 2003. At its location off Rocky Island’s south side, it enjoys some of the clearest water in the Red Sea, making it easy to inspect the wire coral-covered bow and inside the hull. Only a few tec divers visit the site each year, making it among Egypt’s least-documented wrecks.
Length Overall: 500 feet
Depth: 394 feet
Dive the Red Sea with Aggressor.

M.S. FRANKEN
Gdansk, Poland
In 1945, the Soviet Air Force downed this armed oil tanker that supplied vessels including the German cruiser Prinz Eugen. Thanks to the low salinity and low oxygen levels of the Baltic Sea, the Franken, though split in two, has stayed well preserved; find it starting at a depth of 154 feet.
Length Overall: 581 feet
Depth: 236 feet

H.M.H.S. BRITANNIC
Kea Island, Greece

At 12,000 feet deep, Titanic lies beyond the reach of anyone not owning a submarine — but its sister ship is possible for those with the technical wherewithal. Sunk by a mine in 1916 while it operated as a hospital ship, Britannic was discovered in 1975 by Jacques-Yves Cousteau. She now lies on her starboard side, largely intact, save for the bow.
Length Overall: 883 feet
Depth: 400 feet

M.S. ZENOBIA
Larnaca, Cyprus

A glitch in the software sunk this Challenger-class car ferry on its maiden voyage in 1980: Rather than pump water out, more water was pumped into the port side ballast tanks. It’s an easy vessel to reach, lying less than a mile from shore and starting at a depth of 60 feet. It sunk with its entire cargo, mainly trucks, several of which remain on the top deck. Easy penetration routes lead to the canteen and bridge; the majority of trucks are spread between an upper and lower deck.
Length Overall: 584 feet
Depth: 138 feet
Bonus: A truck freighted with the bones of once-frozen animals lies on the lower car deck just before one enters the overhead structure.

R.M.S. LUSITANIA
Kinsale, County Cork, Ireland

Ireland holds a tight grip on the permits shrouding “Lucy” in red tape. Even Gregg Bemis of New Mexico, owner of the British passenger liner sunk in 1915 by the U-20, needs their say-so to recover further artifacts, including paintings by Rubens and Monet rumored to be inside. Another push to further explore the site, as cited by local tec diving club Cork Sub Aqua, is to learn why it sank in just 18 minutes; sister ship Titanic took longer than two hours before slipping from sight.
Length Overall: 787 feet
Depth: 306 feet
Bonus: Also yet to be recovered: the captain’s safe, the bridge telegraph that recorded the captain’s last command and the triple-chime steam whistle.