Unrecovered Shipwrecks & Equipment for Locating Them

By Daniel Bernzweig

Sunken treasure ships are strewn across the ocean floors, from Roman vessels carrying classical sculptures to gold-bearing blockade runners of World War II. There are billions of dollars in gold, silver, jewelry, rare coins, and valuable cargoes that have never been recovered. Books and detailed accounts can tell you the history, location, and cargo aboard these lost ships. Generations have speculated about what caused their peril. There are stories of Chinese "junks" that capsized in the shark-infested Chinese Sea. "Junks" were ships that sailed long distances as early as the 2nd century CE. You may have heard of ill-fated Spanish galleons laden with jewels and coins. Another well-known lost treasure ship was Napoleon’s flagship, the Orient—which carried lavish works of art, solid silver statues, and other antiquities. It would be impossible to track down every lost ship throughout the eras of seafaring. However, it is intriguing to investigate well-known sunken vessels (yet to be recovered) that transported treasure. A magnificent diversity of artifacts, cargo, and precious metals lay waiting to be discovered.

Diving for shipwrecks and the equipment for finding them.

Salvage equipment is vital for the success of any marine service salvage operation. Salvage teams must be properly equipped to deal with various circumstances, including bad weather, strong currents, and debris. The right gear can distinguish between a successful salvage operation and a costly failure.

There are many different types of marine salvage equipment, but some of the most important underwater salvage equipment include:

  1. Winches & Cranes
  2. Grappling hooks
  3. Pontoons & Tugs
  4. Diving gear
  5. Sonar equipment
  6. Marine airbags

This marine equipment is used to locate, secure, and ultimately raise sunken boats and vessels or their cargo. Ship salvage is an essential part of salvage services as it can prevent environmental disasters and protect marine life. While commercial diving can involve danger, locating a sunken boat, or yacht can be exciting. Professional salvors and others performing salvage activity are typically well versed in the specialized salvage equipment required for their operations. We will cover all in this article, which may be a review or refresher for some, and may help to reduce marine casualties by helping others prepare better.

1. Winches & Cranes

Winches and cranes are two of the most important pieces of salvage equipment. Winches are used to pull boats or vessels onto land or a dry dock, while cranes are used to lift them out of the water. Both winches and cranes must be able to withstand the weight of the boat or vessel being salvaged.

Winches are used for wreck removal to pull wreckage and debris from the water. They come in various sizes and capacities, so it is important to choose the right winch for the job. Cranes are also used to remove smaller pieces of debris and wreckage. They are often used in conjunction with a winch to move larger items like barges in the water and for underwater construction projects.

2. Grappling Hooks

Grappling hooks are another important piece of salvage equipment. They are used to secure boats or vessels to a crane or other lifting device. Grappling hooks must be made of strong material, such as steel, and have sharp points so they can easily grip the hull of a boat or vessel. Emergency response teams and salvors often use grappling hooks to secure ships or vessels in the water so they can be safely lifted to shore.

3. Pontoons & Tugs

Pontoons are used to provide buoyancy and stability during a salvage operation. They are often used in conjunction with a crane to lift a boat or vessel out of the water. Pontoons come in various sizes and shapes, so it is important to choose the right one for the job.

Tugs are used to tow boats, containers, or vessels to shore. They can also be used to push barges in the water. Tugs come in various sizes and have different engines depending on the size of the boat or vessel being towed. Tugboats can also assist boat owners with towage and docking their vessels.

4. Diving Gear

Divers are an essential part of any marine salvage team. They are used to survey damage and wreckage, identify objectives, and attach lines and cables to boats or sunken vessels. Divers must be properly equipped with diving gear, including a wetsuit, mask, fins, and tanks. Lift bags are also commonly used by divers to lift them or other small items from the water using buoyancy. 

Diving service companies often have a variety of diving gear that can be used for different salvage operations, whether it is deep diving or operations in shallow water.

5. Sonar Equipment

Sonar equipment is used to locate sunken boats, vessels, and their cargo. It can also be used to map the seafloor and identify potential hazards. Sonar equipment is an essential part of any marine salvage operation. Coast guard personnel and other emergency response crews use sonar equipment to locate people in the water and to find boats or vessels that have sunk.

In the United States, the east coast is home to some of the busiest ports in the world. New York, Baltimore, and Norfolk are just some major cities with port facilities. These ports handle a large amount of maritime traffic and are often in need of salvage services.

The east coast is also home to many shipyards that build and repair boats and vessels. These shipyards often have their own salvage teams and sonar equipment to handle any accidents or incidents that may occur. While these ports are busy with repairs and the like, west coast ports handle many freight and international cargo shipments as well.

6. Marine Airbags

A marine airbag is a type of inflatable device that is used to provide buoyancy during a salvage operation or boat launch. Marine airbags are often used with a crane to lift a boat or vessel out of the water. They are also used to provide buoyancy during the launch of a boat or vessel. Marine airbags come in various sizes, so it is important to choose the right one for the job.

These bags are also utilized to protect floating structures, like docks and piers, from damage during construction or other boats and equipment in the water.

If your salvor operation requires underwater demolition, some or all of these items maybe be helpful. It is up to each individual boat owner to select the tools and marine hardware equipment they will need for their operation. Many of these items are helpful for those towing a stranded vessel as well.

Parties Interested in Shipwreck Salvage

Shipwrecks are the result of an accident or act of war. Some people believe that these wrecks should be undisturbed to preserve the sanctity of lost lives. However, this has not been popular belief. Countries worldwide have sent salvage teams underwater to recover artifacts and gold. Even countries that originally designated ships as war graves later decided to salvage their gold. There are various reasons why people are interested in shipwreck salvage. Underwater archaeologists seek to identify artifacts as priceless maritime history. Treasure hunters and salvors are driven by their own passion. Some are in it for the potential for financial gain. Others love marine and underwater history. But typically, divers are most attracted to exploration and the chance to enter a different historical period. A shipwreck is a perfectly preserved time capsule. Its discovery is only made possible through modern technology—such as remote-operated vehicles, side-scan sonar, and fiber-optic cameras.

Who Owns the Rights to a Shipwreck?

Legal complexities abound when it comes to shipwreck salvage. To make matters even more complicated, laws are always in transition as well. Be sure to seek professional legal advice before undertaking a salvage operation. A common misconception is that anything found by a diver or salvage team is fair game. Unfortunately, that is not always the case. The issue of territorial and international waters comes into play. Some countries, such as China and the Philippines, claim exclusive rights over all wrecks lost within their waters if the ships have been there for several years. And every country has its own definition of the extent of its territorial waters. Typically, it is 12 miles out; however, Thailand claims a much further distance. One salvage team learned the hard way when Thailand seized the treasure they had recovered. Many countries offer a generous salvage award to encourage divers who locate wrecks to declare their finds. Australia operates strict underwater archeological policies, as do France, Spain, Greece, and Portugal. However, Britain, the U.S., South America, and the Far Eastern countries attempt to accommodate salvors. In other words, they balance the interests of the diver(s) with the need to protect important historical underwater sites.

Seafaring and Shipwrecks throughout the Ages

Seafaring was among the earliest forms of transportation—necessary for exploration and trade. As impressive as these ships proved historically, their rudimentary design was often no match for Mother Nature. There were several reasons why ships wrecked—they succumbed to gales or hurricanes, ran aground rocks, caught fire, were bombed by enemies; the list goes on. Below are examples of ships throughout the ages transporting valuable cargo. Billions of dollars in currency and goods are believed to be lost and still submerged.

  • Roman merchant ships of the Bronze Age - Egyptians, Phoenicians, and Greeks bought and traded gold, bronze, precious stones, and raw materials. Their cargoes carried precious stones, exotic animals, silks, steel, and iron. Recovered ships have provided archeologists valuable insight into ancient civilizations.
  • Chinese junks - merchant ships that traveled vast distances starting around the 13th Century. Junks were sturdy; efficient ships were used to trade Chinese goods. Cargoes often included gold, silver, porcelain, silks, sabers, and specialty teas. They traded for ebony, ivory, gems, pearls, coral, and exotic animals (such as tigers and crocodiles).
  • Venetian merchant ships - made frequent voyages from 1000-1500. They exported gold and silver coins and gold bullion to purchase oriental spices, silks, pearls, precious stones, and porcelain.
  • Portuguese carracks - three- or four-masted sailing ships developed in the 15th century for use in the Atlantic Ocean. Carracks became widely used by Europe's maritime powers. They traveled in fleets to trade with India. Only 4 out of 5 ships survived the trip.
  • Spanish galleons - regularly traveled between Spain and the Americas, transporting goods to settlers in the New World. Gold and silver bullion was traded for merchandise. By the end of the 16th Century, fleets were known to bring back over 3 million pesos at a time. Bullion was stamped by Spanish authorities in the Americas.
  • Spanish shipwrecks were responsible for losing millions of dollars in silver, gold, and porcelain. Galleons perished due to storms, raids by pirates and privateers, and running aground on reefs.
  • The Spanish galleon Atocha was the most famous of a fleet of ships that sank in 1622 off the Florida Keys while carrying copper, silver, gold, tobacco, gems, jewels, jewelry, and indigo. Salvage diver Mel Fisher discovered the galleon in 1985 after a 16-year search.
  • Age of the Revolution - between 1775 and 1800, a war broke out between Britain and revolutionary France. French privateers attacked British merchant ships across the globe. During this time, Napoleon seized Dutch and Spanish fleets plundering valuables and treasure. In an ironic twist, British ships then overcame their fleet carrying 3 million francs in valuables. The famous Orient subsequently sunk and, with it, millions in valuables.
  • World War II - between 1939-1940, a staggering amount of warships and ocean liners evacuated from Europe carrying gold and valuables. Countless numbers were attacked by German U-boats, sunk by planes, and torpedoed by submarines.
  • The rush for gold - The American gold rush began in 1848 and attracted prospectors worldwide. Miners returning to Europe frequently lost their entire cargo of gold. Central America departed Panama and wrecked with approximately $1 billion onboard. This included 3 tons of gold, $35 million in bullion, newly minted double eagle coins, and pioneer coins. In 1987, an American salvage team used a remote-operated vehicle to recover part of the treasure.
  • Pirates and privateers - these infamous groups made it their business to seize goods being transported at sea. Pirates acted on their own behalf, while privateers were sponsored by a specific party. Privateers were instructed to carry out an act of war. They kept a percentage of their spoils and gave the rest to the Crown. The NS de Guia was captured and sunk by English pirates in the Atlantic. At the time, it was laden with gold, silver, and pearls.

Examples of Unrecovered Ships and Cargo

  1. Spanish ship Ferrolena Urca: sunk off of the coast of China in 1802
    Cargo: silver- $1.8 billion lost. Some looting & salvage at the time of loss.
  2. British ship Ardaseer: sunk in the Andaman Sea en route to India in 1851
    Cargo: a large quantity of specie (coin money). Some salvage before the ship sunk.
  3. British ship Parsee sunk near Indonesia in 1845
    Cargo: very valuable, including specie. Partly salvaged at the time of loss.
  4. Dutch East Indiaman Hercules sunk near Sri Lanka in 1661
    East Indiaman ships carried both passengers and goods; they were armed to defend themselves against pirates. Cargo: gold and silver. Never salvaged.
  5. Portuguese ship Arrelikias was lost off the coast of India in the 16th Century.
    Cargo: chests with gold and jewels. Divers only recovered a few chests.
  6. Dutch East Indiaman Dageraad hit rocks near South Africa in 1693
    Cargo: 17 chests of treasure. Never recovered.
  7. Italian ship San Michele lost near Alexandria, Egypt, in 1479
    Cargo: many valuables—some believed to be unreported. Never recovered.
  8. Spanish ship Nuestra Senora DeGuia sunk near the Azores Islands in 1589, Attacked by English corsairs (Duke of Cumberland’s expedition)
    Cargo: the undisclosed amount of treasure. Partially looted at time of loss.
  9. British warship Lexington sunk near Long Island Sound, NY, in 1780
    Cargo: rumored to be gold. Never recovered.
  10. Spanish ship San Pedro went down near Guam in 1569
    Cargo: gold and porcelain. Never recovered.

Metal Detecting Equipment for Shipwreck Discovery and Salvage

Divers and salvage teams rely on modern metal detection technology to locate sunken treasure ships. After carefully researching and mapping out the geographical search location, marine salvage experts use detection devices to map the seafloor and search for wreckage. State-of-the-art underwater equipment includes boat-towed metal detectors, magnetometers, ROVs, lighting and camera/video devices, pingers and receivers, and hand-held underwater metal detectors.

A tow-fish or boat-towed metal detector is often the first device implemented when initially locating a shipwreck. Boat-towed metal detectors come with long cables that are dropped from a search vessel; they signal upon locating ferrous (iron, steel) or non-ferrous (gold, silver, bronze, etc.) targets. Boat-towed detectors offer a deep detection area (ex. 24-feet-wide and 16 feet deep). This makes them ideal for zeroing in on cannons, anchors, propellers, airplanes, shipwrecks, and buried pipelines. Magnetometers are the most powerful boat-towed metal detectors for iron and steel. They compare the intensity and direction of one magnetic field to another. Since ships deteriorate over time, salvage experts must look for metal targets such as anchors, hull parts, cannonballs, and weaponry. Magnetometers are highly proficient at locating these targets; they cover large areas of the seafloor in short periods of time.

Boat Towed Metal Detection Devices:

Many marine salvage teams use highly sophisticated underwater submersibles called ROVs (remote-operated vehicles). ROVs can dive to 4,000 meters and beyond. The deepest part of the world’s oceans reaches 37,000 feet; more frequently, the ocean floor ranges from 5,000 to 20,000 feet deep. This makes unmanned inspection devices essential. ROVs are used to survey a shipwreck and take photos and videos to create detailed imaging of the scene. Equipped with manipulated arms, ROVs can be programmed to search a shipwreck and convey the precise location of each artifact via a computer program. ROVs are powered by jet propulsion to thrust the vehicle forward and backward as well as vertically and laterally. They are operated top-side by a controller in the search vessel. ROVs are custom equipped with all of the options necessary for a salvage team. When recovering small, fragile objects, precious bullion, coins, and ingots, it is also essential to use underwater lighting, camera and video equipment. This allows the salvors to view and properly record their findings. Marine salvage equipment is expensive, but it can pay off dividends in treasure discoveries and contracts from countries looking for salvage work. Huge salvage companies like Odyssey Marine Exploration spend millions of dollars on underwater marine salvage equipment. Be sure to read our related article entitled "What are the Best Metal Detectors for Underwater Search & Recovery?" for complete details.

Remote Operated Vehicles (ROV):

Remote Operated Metal Detectors:

Underwater Light Systems:

Underwater Camera & Video Systems:

To read about underwater pingers and pinger receivers as well as underwater sonar systems, check out this article in our Learning Library: What are the Best Metal Detectors for Underwater Search & Recovery?

MetalDetector.com carries a large selection of underwater equipment for both recreational and commercial divers. If your team is serious about recovering treasure ships, be sure to research and select the best equipment for your project. Our product specialists can help you find customized detection devices to set you up for success!

Copyright 2014 Detector Electronics Corp. - Revised September 2022