People have been constructing artificial reefs for thousands of years. Ancient Persians and Romans used to construct reefs from rubble to prevent enemy ships from navigating safely, and in 17th Century Japan, rocks and rubble were used to grow kelp. In the Unites states, American fishermen began constructing artificial reefs in the 1830’s. While subway cars and vintage military equipment, oil drilling rigs and automobiles have found their way into artificial reefs, so have boats and ships of all kinds. When you think of wreck diving, what comes to mind? Artificial Reef Wrecks, or Accidental Wrecks? Each has its own characteristics and hazards. Let’s take a look.
Artificial Reefs Have Often Been Prepared for Safe Wreck Diving
To prepare a vessel for sinking as a wreck dive site, it is first purged of any dangerous chemicals, including hydraulic fluid, oil, and any fuel or PCB’s. This protects both divers and the environment from coming into contact with hazardous materials. In addition, much of the superstructure is often removed, as this portion of a wreck is often the first to cave in from corrosion. Interior surfaces are cleaned and gutted of entanglement hazards or any dangerous objects. Sometimes, murals are painted or commemorative plaques are added. Finally, openings are widened, and holes are added to the ship’s hull to create safer penetration opportunities.
While some wrecks are simply towed to planned artificial reef sites and sunk unceremoniously, ending up on their sides or even upside down, the largest and most popular artificial wrecks, like the USS Constellation or the HMNZS Wellington for example, are carefully ballasted with water, towed to the sinking location, and scuttled via controlled demolition, intentional flooding, and other methods. Engineers do their best to ensure that these planned wreck sites land upright, and in some cases, lift methods are used to right ships that have landed at an angle. Positioning wrecks upright helps to make them safer to explore, allowing their structural integrity to remain intact for a longer period of time.
Artificial wrecks often make excellent first wreck dives and can be exceptional places to learn to dive in overhead environments. In addition, they often have amazing features and incredible stories that add to the excitement of diving. On the flip side, there are normally no new discoveries to make, and artifacts are firmly cemented into place! Still, treasure exists in the form of fantastic marine life.
Artificial reefs in popular diving areas help to take diving pressure off natural reefs, plus they provide important habitats for marine life. While disaster wrecks often perform the same function, they are often more dangerous to dive; although in some cases they can be much more exciting to explore.
Diving Disaster Wrecks – The Risks Can be Greater; So Can the Rewards
Shipwrecks and aircraft wrecks happen for a variety of reasons. In some cases, owners scuttle unwanted or worn out vessels, although this often happens in deep water. In cases like these, everything of value is normally removed from the ship before it is sunk or abandoned. Exterior and interior structures are notoriously unstable, and dangerous chemicals can pose a threat.
Accidental wrecks are often associated with tragedy, and many of them are grave sites. The stories behind these wrecks are compelling, but in some cases, particularly in cases where explosions occurred, there are lots of sharp edges and entanglement hazards to watch for. Some are reputed to be haunted; for instance, the SS Yongala in Australia is notorious for sending tingles up and down divers’ spines.
In addition, wrecks that are not intentionally added to the environment as dive sites have a greater tendency to be covered in old fishing nets and fishing lines. These hazards can occur on planned wrecks; however well-known accidental wrecks are often targeted by fishermen. Carrying a sharp dive knife and practicing awareness as you explore can help to mitigate the risk of entanglement.
While many accidental wrecks are in shallow water, and while their exteriors are fun for newer divers to explore, most wrecks that have occurred by accident or during the course of combat are more dangerous to penetrate than those that have been prepared for safe diving. In addition, hazardous materials may be present – these include everything from unexploded ordinance, to oil and other fluids that can be trapped inside compartments.
The danger of collapse or entrapment is often very real on disaster wrecks. Falling objects and collapsing walls can injure or kill divers; in addition, they can cause entrapment. Artificial wrecks are normally monitored and maintained to prevent this from happening. On artificial wrecks, compartments that are meant to be accessed by divers have double exits that help to increase the safety margin.
Poor visibility is another factor to consider; especially inside some of the oldest wrecks, your bubbles can cause matter to fall from overheads and bulkheads, and in some cases, heavy silt can reduce visibility to zero in the blink of an eye. On the most popular artificial wrecks, the steady stream of divers and the large openings tend to reduce the risk of silt accumulation.
Guide lines, redundant lights, mixed gases and redundant air supply, and other equipment are often essential to safety and comfort on wreck dives, but they are no substitute for appropriate training and progressive experience. Familiarize yourself with famous diving accidents – learning from mistakes others have made can help you to prevent yourself from making the same or similar mistakes.
Another important consideration on historic wrecks is that many are protected by law. Familiarize yourself with laws in areas where you plan to dive to avoid costly fines, equipment confiscation, or even imprisonment. In most places, diving is permissible but taking artifacts is not. A safe practice is to leave artifacts behind for others to enjoy; if you are interested in collecting artifacts from shipwrecks, then consider becoming part of an underwater archaeology team, or dive in places where artifact removal is acceptable and expected.
If you’re fascinated with shipwrecks and love maritime history, then be sure to take a wreck diving course and become familiar with safe practices before attempting to penetrate any wreck, even one that has been carefully prepared for divers. Training, wreck, and technical certifications are well worth the effort and investment – along with fun and famous artificial wrecks, there are thousands of disaster wrecks to explore throughout the world. As new advances in dive technology are made, we can explore deeper and more mysterious wrecks, gaining greater understanding along the way.