How Safe Are Submarine Tours?

And what’s the difference between a submarine and submersible? All your questions answered following the recent “Titan wreck.

Underwater in the Scenic Neptune

Some cruise companies, like Scenic, offer submarine tours to their guests.

Stefanie Waldek

On June 18, an experimental submersible carrying a pilot and four passengers to the wreck of Titanic went missing. After several days of search-and-rescue operations, authorities determined the sub, OceanGate Expedition’s Titan, had suffered a catastrophic implosion, killing all onboard.

The incident has understandably caused public concern about the submarine industry at large, and travelers who have booked or are looking to book sub trips might be having second thoughts. But are they warranted?

It’s natural to be a little nervous about diving in a submarine or submersible—they are, after all, enclosed environments that take you beneath the sea. But generally speaking, there’s not much cause for worry.

“A certified submarine is a lot safer than public perception. Of course, there is risk when boarding a submarine, just as there is risk when you board a plane or get in your car,” says Mckenzie Margarethe, marine naturalist and former submarine copilot for Atlantis Submarines. “However, for most touring submarines, it is uncommon for things to go wrong. Every potentially dangerous scenario has been evaluated, and an emergency plan is developed with the crew training on it regularly to ensure proficiency.”

Here’s what you need to know before you book a submarine or submersible tour.

What happened to the “Titan”?

Titan was an experimental submersible designed by OceanGate Expeditions to bring tourists to the Titanic wreck site deep in the North Atlantic Ocean—about 12,500 feet deep. On June 18, during a scheduled dive, the expedition team lost contact with the sub, prompting a multiday search-and-rescue effort by international groups. Debris from the sub was discovered by a remotely operated vehicle (ROV), indicating that the vessel suffered a catastrophic implosion that killed the five people onboard, including OceanGate CEO Stockton Rush, who was piloting the sub. While the investigation is ongoing, it is likely that the sub’s pressure hull, the pressurized compartment for passengers, failed in some way, and the pressure of the surrounding water caused it to implode.

What’s the difference between a submarine and a submersible?

Submarines and submersibles are both underwater craft. Submarines operate independently—they can sail into and out of ports under their own power. Submersibles rely on support ships or platforms for their operations, including transportation to and from dive sites. Titan was a submersible that operated from the support ship Polar Prince, a former Canadian Coast Guard icebreaker. Both submarines and submersibles are used for tourism, with the former popular in island destinations like Hawai‘i and the Caribbean, and the latter more common on expedition cruises.

How safe are submersibles?

When you look at the safety record for classed submersibles, you’ll find that they’re far safer than planes and cars in terms of fatalities.

“Classed or accredited human-occupied vehicles (submersibles) have enjoyed an enviable and unblemished safety record for more than 50 years,” says a spokesperson from Triton Submarines, a private submersible designer and manufacturer. “Collectively, classed subs from around the world carry more than 1 million people a year on dives and have done so for almost four decades without a single fatality.”

The key here is that those submersibles are all certified, or classed, by third-party classification societies. OceanGate, on the other hand, intentionally did not seek classification for Titan. According to a now-deleted blog post on the company’s website, certification would have taken too long and been “anathema to rapid innovation.”

Naval submarines, however, have had numerous fatalities; the U.S. Navy has lost thousands of submariners, mostly due to warfare rather than accidents, but accidents have happened. The Navy has vastly improved submarine safety through the SUBSAFE quality assurance program, which was implemented in 1968 and has since dramatically reduced major incidents.

What oversight exists in the submarine and submersible industry?

Legally, there isn’t much oversight at all—there are no international laws governing submarine and submersible operation. But submarine and submersible operators typically do take it upon themselves to certify their vessels for safety, which is often required for insurance purposes. “Naval submarines are certified by the Navy, and private submarines are certified privately,” says Margarethe.

Private certification is handled by third-party classification societies, of which there are many around the world, including DNV and Lloyd’s Register. If you plan on taking a sub tour, ensure that your vessel is classed by a society. “Certification requires an arduous, time-consuming, and thorough independent appraisal of every aspect of the design, production, and operation of a human-occupied craft,” says the Triton spokesperson. The process analyzes everything from material selection to system operations, and it includes a dive to the maximum operating depth.

Classing isn’t a one-and-done sort of deal; it continues throughout the lifespan of the sub. “Although the class inspection interval varies slightly between the different certification agencies, all of them require annual surveys,” says the Triton spokesperson. “The class society will annually inspect the hull, structure, safety systems, life support equipment, and the functioning of mechanical, fluid, and electrical systems.” Triton subs also undergo more in-depth surveys at longer intervals, with class renewal every five years.

What are your options for rescue if something goes wrong?

Subs have numerous ways to surface, so if one system fails, another will kick in. For example, most subs have a “drop weight” on the bottom, which helps with balance under normal circumstances but can also be jettisoned to cause the sub to surface.

But in the event a sub does get stuck at the bottom, most will be at a depth where undersea rescue is possible, whether by divers or another sub. “For the submarine I worked on, we also didn’t go below 150 feet with passengers on board as a safety precaution. This is because in case of emergency, there are vents a scuba diver could access that would fill our ballast with compressed air and bring the submarine to the surface,” says Margarethe. By contrast, Titan was diving to 12,500 feet, the depth of the Titanic wreck.

One thing to consider, however, is the location in which you’re diving. A number of new expedition ships carry submersibles, which can be deployed in remote and sometimes dangerous environments like Antarctica. In these remote locations, rescue may be much more difficult, given how long it might take rescue crews to arrive or other variables like sea ice.

Inside the Scenic Neptune.

Inside the Scenic Neptune.

Stefanie Waldek

Should you take a sub tour?

Sub tours offer a perspective of the ocean that most people don’t get to see, and so long as the operator adheres to proper protocols such as classing and regular inspection, they’re a safe way to witness all sorts of sea life. Of course, there’s always some level of risk involved, particularly in remote environments, which is a judgment call you’ll need to make for yourself.

But there are benefits to underwater tourism. “You have a tour guide that can tell you about everything you’re seeing and help you develop a connection with the water,” says Margarethe. “I believe it’s important we foster a connection with the water in as many people as possible, seeing as it makes up the majority of our planet and desperately needs our help and attention.”

I took my first submarine tour on a family vacation to the U.S. Virgin Islands when I was a child; we booked seats on an Atlantis Submarine vessel. Admittedly, I didn’t pay much attention to the operational details, but I do recall being mesmerized not only by the flurry of sea life around us but also by the change in color perception as the water absorbs different wavelengths of light the deeper you go. Atlantis subs fit several dozen passengers who can look out of viewports that run the length of the vessel. Because the sub is so large—or perhaps because I was so small at the time—I didn’t feel particularly claustrophobic.

Last year, I made my second dive, but this time in Antarctica. The luxury expedition ship Scenic Eclipse has a submersible named Scenic Neptune that carries six passengers plus the pilot, with the passengers seated in two large acrylic spheres that provide 280-degree views. Though the sub was far smaller than the Atlantis sub, these spheres made it feel rather spacious. The only claustrophobia-inducing moment is climbing through the narrow hatch and down the ladder.

The sea life in Antarctica is, of course, vastly different than what you’d see in the Caribbean. But knowing that this underwater world is so infrequently seen by “normal” people like me, I was completely captivated by all signs of life, from tiny krill to massive sea sponges. I was, however, a touch nervous to make the dive. Knowing how unpredictable conditions can be in Antarctica from a previous voyage, I worried that something could go wrong. Though my 45-minute dive went off without a hitch, Scenic Neptune did have an incident in November 2022; a powerful weather phenomenon called katabatic winds pushed ice floes over the sub, damaging it slightly, and keeping guests underwater for a couple of hours. All passengers and crew returned to the ship safely.

Questions to ask your tour provider

If you’re nervous about booking a sub tour, here are some questions you can ask your operator to address your concerns.

Is the sub classed and by whom?

Classification by a third-party is a crucial safety measure in the private sub industry.

How often do you inspect the sub?

Subs should be inspected between each dive.

What is the maximum depth the sub can dive to, and how deep will we go on our dive?

Most submarine tour operators will not dive to their subs’ maximum depths—and that’s a good thing. Better safe than sorry.

How long can the sub stay underwater in an emergency situation?

Find out about the oxygen supply onboard, as well as stores of food and water.

If the sub gets stuck on the seafloor, how will we be rescued?

Tour operators should be able to answer this question with ease, as they should have numerous safety plans in place.

Does the sub have an emergency beacon that will broadcast our location in an emergency?

Most submarine tour operators will have an escort vessel on the surface to monitor the sub closely. But it wouldn’t hurt for the sub to have an emergency position-indicating radio beacon (EPIRB) or submarine emergency position-indicating radio beacon (SEPIRB) onboard, both of which will broadcast the sub’s location in an emergency (the former works on the surface, and the latter works underwater).

Stefanie Waldek is a space, travel, and design journalist who loves aviation, storm chasing, and The X-Files. She’s happiest when cruising at 36,000 feet or at sea level in polar regions.
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