Wreck Diving: A Diver’s Guide
To dive on a sunken wreck is to take a trip back in time. Ensconced in their watery graves, these mysterious relics of the past can be found nestled on the bottom of oceans, lakes and rivers in all corners of the world. Whether they found their fate as a result of wartime hostilities or accidents or were sunk intentionally, descending onto a sunken wreck can be an adrenalin-pumping undertaking.
Sunken wrecks can include just about anything that once floated or flew. You can find military ships – from massive aircraft carriers to submarines, former luxury cruise ships, commercial work vessels like tug boats, fishing boats and kelp harvesters, as well as private vessels like power yachts and sailboats. You can also find airplanes, collapsed research platforms and even a car or two. They sit at various depths, in both clear warm water and green cold water. Some are virtually intact, others show only remnants of their former glory, but all are tantalizing lures to any diver with a thirst for adventure.
Why Wreck Dive
The reasons divers seek out sunken wrecks are probably as varied as the divers themselves. Some are just there to do some sightseeing, seekers of something new to look at beyond the walls, reefs and coral outcrops they normally encounter at depth. Others take it a bit more seriously.
For these divers wreck diving is driven by the pursuit of science, a love of history, or the lure of potential treasure, all spiced with a sense of exploration and discovery. To cruise over the super-structure of a Navy warship; to enter the ship’s bridge and grab hold of the steering wheel; to drift through the galley strewn with abandoned cups and plates; to drop into the engine room where the pistons of massive machines once pumped – it takes you back to a bygone era. It’s mystery and history, eerie yet awesome, all rolled up in one spine-tingling experience.
Rules for Wreck Diving
Every diver who has dropped down on a wreck must have, at some point, entertained the wistful notion of finding sunken treasure, or perhaps some priceless artifact. However, in reality, even if you do find something of value on a sunken wreck, chances are you won’t be able to keep it. Even if what you find has no apparent monetary value – like a brass porthole or a ship’s bell or even plates and cups – there are a myriad of laws that protect sunken wrecks from treasure seekers. For example, in the state of California, any wreck more than 50 years old belongs to the state and, therefore, any objects retrieved from it can be confiscated by state authorities. Many other states have similar regulations.
Some wreck divers will argue that these laws make a lot of sense, that they help preserve the integrity of historically significant dive sites for the wreck divers of tomorrow. Others will argue that artifacts left untouched will eventually disintegrate and will therefore be no good to anybody. Wherever you may land on the subject, based on current laws, in the U.S. as well as in many other regions of the world, the best course of action may be to “enjoy the visit, but take only pictures.”
If you’re diving a sunken wreck from a commercial dive boat the skipper or dive master will be familiar with the rules and will fill you in on any restrictions that may apply when visiting the wreck. If you’re diving from a private vessel, before hitting the water make sure you do your homework. Find out if there are any laws affecting the wreck you’re going to visit and follow them. Not doing so could mean potential fines and the confiscation of your dive gear.
Types of Wreck Diving
Wreck diving is broken down into three basic categories: non-penetration, limited-penetration, and full-penetration.
Non-Penetration Wreck Diving
The most basic, and least hazardous, type of wreck diving is non-penetration. On this type of wreck dive you never actually enter the wreck; rather, you swim around and over it. There might be portholes or windows you can peer into, a superstructure you can soar over or an airplane wing you can sit on, but you never actually go inside. These wrecks can be a lot of fun to visit and they offer a great introduction to wreck diving as a specialty sport.
If you have the dive skills and enough underwater experience to be comfortable at the depth the wreck sits at, you should be able to dive a non-penetration wreck without any special equipment or training beyond an open water certification.
Limited-Penetration Wreck Diving
Limited-penetration wreck diving enables you to enter certain areas of a wreck while staying within the “light zone” – those areas illuminated by ambient light, with exits always visible. Many limited-penetration wrecks were intentionally sunk to serve as both dive sites and artificial reefs. Because of this, they have been “prepped” for diving, meaning that before being sunk they underwent a thorough cleaning to get rid of environmental hazards. They were also stripped of potentially dangerous gear, doors and hatches were removed, and holes were cut into the hull to maximize access and allow in additional light.
For this type of diving you usually don’t need specialized gear beyond some wreck diving-oriented accessories. However, by going inside a sunken wreck, even a little bit, you’re exposing yourself to the wreck’s internal structure which can increase the possibility of entanglement in things like loose cables or getting snagged on sharp edges. More importantly, going inside means you’ll be diving in an overhead environment. Consequently, limited-penetration wreck diving requires more dive experience, a solid level of comfort at depth, and better dive skills, so taking a wreck diving course is highly recommended.
Full-Penetration Wreck Diving
Full-penetration wreck diving, also referred to as advanced wreck diving, allows you to venture deep into the interiors of sunken wrecks far beyond the “light zone.” Combine this with the fact that many full-penetration wrecks are found at extreme depths and that they haven’t been prepped for safety, and the risk factor ratchets up considerably. This is wreck diving at its most serious. This is considered full-blown technical diving, requiring special equipment, lots of backups, advanced navigational skills, a thorough knowledge of mixed gases, tons of deep diving experience and intensive specialized training.
Hazards of Wreck Diving
Wreck diving carries with it risks you generally won’t find in other types of diving. While swimming around superstructures or along a cluttered deck, entanglement from discarded fishing nets or monofilament line are things you must always watch out for. Wrecks that have been on the bottom for long periods of time also start to deteriorate and pieces break off, creating jagged edges that can snag a piece of gear or slice the leg of your wetsuit.
When you move into full-penetration dives a number of additional hazards present themselves, from something as simple (but serious) as striking your head on an overhead beam in low-light conditions, to losing your way down a maze of corridors, to getting stuck while trying to negotiate a tight passageway, to running out of air. Some wrecks get filled with silt or mud that can get stirred up surprisingly easy, destroying what little visibility you might have and creating serious challenges in maintaining your orientation.
The best way to mitigate the hazards of wreck diving is to be prepared, and you get there by being properly equipped, extremely well-trained, and having lots of underwater time logged to ensure that you’re comfortable in the water and have confidence in your dive skills.
Equipment for Wreck Diving
For most non-penetration wreck diving you don’t really need much more than your standard recreational dive gear. However, limited-penetration dives and full-penetration dives require additional equipment. Following are some examples of equipment designed to increase your safety margin when wreck diving.
Redundant Air System (RAS)
A redundant air system (RAS), also called a bail-out system, is a completely separate and independent breathing rig designed to provide you with an emergency air source in the event that you experience a malfunction or deplete your primary air source. RAS units come in a variety of sizes, from the compact Spare Air to a pony bottle complete with dedicated regulator. The one you choose will depend on how deep you plan on going and how much extra equipment you want to carry.
Dive Light
Dive lights range from powerful canister LED lights to mid-sized hand-helds to compact pocket lights. Many divers will carry at least one of each. In fact, penetration divers are generally advised to carry three lights – a primary light and two backups. Consider a negatively buoyant light that won’t float away if you set it down, that’s armed with a protective shroud to protect the light head from damage, and that includes a security wrist lanyard.
Dive Knife
A good dive knife can be crucial if you become ensnared in ropes, rigging, nets, or fishing lines. Short bladed knives, line cutters and heavy-duty shears are all good choices. Serrated edges work great for sawing cuts and snapping monofilament fishing line, while plain-edged blades tend to cut more efficiently through the rough stuff. Having multiple tools on hand is a good idea for any wreck diving scenario.
Wreck Diving Reel
Having some type of reel as part of your dive kit is a good idea for a recreational diver, and a crucial tool for a wreck diver. Heavy-duty reels that hold a generous amount of line enable you to lay out a guideline as you make your way deep inside a wreck. This ensures that you’ll be able to find your way out again, regardless of visibility.
A Lift Bag or Surface Marker Buoy
A surface marker buoy (SMB) lets you mark the location of a wreck or identify a specific portion of a wreck which can save search time when returning after a surface interval. And if you are able – and allowed – to remove artifacts from a wreck, having a lift bag on hand will make it much easier to get that heavy brass porthole or ship’s wheel back to the surface.
Specialized Gear for Advanced Wreck Diving
Full-penetration wreck diving requires gear that offers the ultimate in performance and reliability. Since many wrecks are found in deep water, high-performance regulators like the MK25 EVO/D420 that are built to breathe flawlessly at the deepest depths and most adverse conditions are must-have items in a wreck diver’s gear bag. Regulators that increase versatility, like the MK25 EVO/G260, enable you to reconfigure the low pressure hose on either side of the second stage casing to accommodate different rig setups, providing a huge benefit in wreck diving scenarios.
Because wreck diving often involves deeper depths and/or longer bottom times, wreck divers commonly dive with two main tanks, each with its own dedicated regulator system. These tanks are connected with a manifold enabling the diver to draw off both tanks using one regulator. At the same time, the manifold is equipped with an isolation valve that enables one tank/regulator to be closed off in case of a leak or malfunction.
Sidemount systems are also commonly used in wreck diving. With a sidemount system the air cell is mounted directly on the back of the harness and the tanks are mounted on each side of the diver, under the arms. This system not only minimizes a diver’s profile, it also makes the tanks extremely accessible for unclipping and re-clipping when moving through tight spaces. In extended-length penetration scenarios, it also makes it easy to pick up staging tanks and drop off empties.
Advanced wreck diving also requires advanced computers that offer the ability to program, monitor and switch between nitrox and trimix (a combination of oxygen, helium and nitrogen). In addition to a Scuba mode, a wreck diving computer also offers a Sidemount mode and CCR mode in the event a rebreather is used. The computer must also provide a maximum operating depth that will accommodate extreme diving depths. And, of course, no wreck diver goes down without at least one backup computer.
Training for Wreck Diving
Basic wreck diving courses teach skills like the proper use of guidelines and reels and air management for negotiating overhead environments while stressing the importance of redundancy in equipment. Most courses focus on training for limited-penetration wreck diving. Go beyond that and you’ll be entering the realm of technical diving.
Here are some U.S. certifying agencies that offer Wreck Diving specialty courses (course descriptions are pulled from their respective websites):
This program develops wreck diving skills within the limits of light penetration and insures that divers are aware of self-responsibility and capable of risk management in overhead environments.
NAUI Wreck Penetration Diver Course:
The NAUI Wreck Penetration Diver course provides the skills and knowledge needed to minimize risks in penetration wreck diving at depths not exceeding 130fsw. You’ll learn about the safety hazards and special risks of overhead environments, gas management, entanglement, limited visibility, NAUI Technical Equipment Configuration (NTEC), the specialized equipment utilized in wreck penetration diving, search methods, underwater navigation, legal aspects, artifacts, treasure, salvage, archaeology, and more.
PADI Wreck Diver Specialty Course:
The PADI course covers safety considerations for navigating and exploring wrecks, surveying and mapping a wreck, using penetration lines and reels to guide exploration, and includes techniques to avoid kicking up silt or disturbing the wreck and its inhabitants.
The SDI Wreck Diver Course covers the equipment and techniques commonly employed while wreck diving. This course may be taught as a non-penetration requiring 2 dives, or as a limited-penetration course requiring 3 dives.
SSI Advanced Wreck Diving Course:
This program allows limited-penetration within the daylight zone into wrecks with an overhead environment. The training required for this type of diving is overhead buoyancy control, new finning techniques, optional laying of safety lines and the proper use of a dive light. The program can be completed wearing a single cylinder with either a pony cylinder or H/Y valve.
The TDI Advanced Wreck Diver Course is the next step for a diver who has successfully completed the SDI Wreck Diver Course. During this course, the TDI Instructor will teach the proper techniques for locating and planning an advanced penetration dive. The advanced wreck course is commonly taught with other popular TDI courses such as Advanced Nitrox, Decompression Procedures, Extended Range, Closed Circuit Rebreather, and Trimix.
Wreck Diving Awaits
There are hundreds of sunken wrecks scattered on the sand and rock bottoms of oceans and lakes the world over. Armed with the right equipment and proper training, touching down onto the deck of a sunken wreck will unlock a world of diving you never thought possible. So dive in –adventure awaits!