Finding and Exploring Shipwrecks in California

The process of identifying, finding, and surveying shipwrecks is very challenging. Like all good detective work, it requires patience, commitment, and attention to detail. Above all, shipwreck discovery is a team effort. It takes a lot of people working together, each contributing their unique talents. Some will do the library work, others operate the boat, some dive on the wreck, and others preserve artifacts if and when the items are brought back from the shipwreck.

Knowing the location of a wreck is a start, but it is often not enough. In some cases, we know that a ship sank, but we do not have an accurate location telling us where it sank. Robert Ballard found out when he discovered the Titanic that where a ship is reported to have sunk and where it is found are often miles apart. Sometimes, we find wreckage but have no idea what ship or ships it came from. Shipwrecks tend to occur in clusters around harbors and anchorages, offshore rocks, and the headlands of islands and the mainland. For example, the wreckage of seven U.S. Navy destroyers that ran aground in 1923 nearly sits on top of the wreck of the Yankee Blade--north of Point Pedernales, at a place called Honda. Wreckage scattered around Point Bennett on San Miguel Island comes from many wrecks from 19th and early 20th century lumber schooners to modern day fishing vessels and maybe even from the mythic 400-year-old Spanish treasure galleon. For a place like Point Bennett that is a "shipwreck salad," the challenge to the shipwreck explorer is to separate the wreckage and correctly identify what ships it came from.

Finding Out About the Wrecks

The key to solving a shipwreck mystery starts in the library, because that is where the clues are often found. Old newspaper stories of the wreck provide the essential details of the 5 W's--who, what, when, where, and why. With this information, we can then find other records such as ship registration and government wreck reports. Each step of the process brings us closer to knowing what the ship was doing, getting a location for the wreck and provides clues about what might be there once we find it.

Who tells us if there are survivors, family members, or rescuers who might be able to tell us more about the ship and the wreck. What gives us details about the ship and its sinking. It tells us what the ship was carrying. If a report tells us that the boat we are looking for had a diesel engine, we might expect to find the remains of the engine in the wreck. If the reports say that the vessel had been almost completely salvaged, we would expect to find only scattered wreckage.  When tells us about the time the ship was wrecked and how long it took to break up. Where gives us a location to start looking for the wreck. Why answers the question about the life and death of a ship. It is not just enough to find and identify wrecks. A shipwreck explorer's curiosity is not satisfied until almost everything that can be known about the ship is known about the ship.

Searching for the Wreck

Library research helps determine the areas of the sea floor that need to be searched. At sea, we use a number of high-tech tools to help us locate the shipwrecks. This high-tech has a special language. A sensor called a magnetometer towed behind the boat measure the earth's magnetic field. When the sensor passes close to iron objects from shipwrecks, like cannons or machinery,
it registers a change in the magnetic field called an anomaly. The boat towing the sensor crisscrosses (mags) the entire area, revealing clusters of anomalies. These clusters help pinpoint the wreck. The bigger the wreckage and the closer the sensor comes to the wreckage, the larger the indication.

Side-scan sonar also helps pinpoint shipwreck sites. The boat tows a sonar transmitter, called a fish, which sends out sound waves. When these sound waves hit wreckage (the target that sticks up above the sea floor,) the wave is reflected back to the sensor. A computer hooked to the sensor records the "sound picture" and the location of the target. Unlike divers towed behind the vessel, the side-scan sonar can "see" through murky water. The most advanced side-scan sonar can detect objects that stick up from the ocean floor as little as 1 foot high. The sidescan image shown above is that of a 190-foot long shipwreck site in the western Santa Barbara Channel, detected during an offshore oil and gas survey. The wreck extends 14 feet above the sea floor.

Another sensor used to detect shipwrecks is a remotely operated vehicle or ROV (pronounced ar-oh-vee). The ROV consists of a television camera in a waterproof housing connected to video monitors on board the vessel by several hundred feet of cable. The ROV has small thrusters attached to the housing. 

The operator on board the boat uses a joystick to send commands that control the thrusters. The operator can "fly" the ROV over the sea bottom while the crew members watch video monitors for wreckage.

Exploring the Wreck

After a wreck is detected, divers go down to explore and map the site. We can learn a great deal about how people lived by carefully studying shipwrecks. Divers use self-contained underwater breathing apparatus or scuba gear. Divers take pictures of the wreckage using photographic and video cameras that are specially designed for underwater work. Divers unreel water-proof tape measures to determine the size of the wreckage. Divers record all this information underwater on slates using ordinary lead pencils.

People argue about whether or not divers should bring back things from the wreck. Many people believe that all wrecks should not be disturbed. Their motto is "take only pictures--leave only your bubbles." Wrecks in national parks and marine sanctuaries are protected--no objects may be removed from these wrecks. People who dive for fun on wrecks outside the protected areas are asked to not take anything from the wrecks. Pretend you are a diver. Think about how exciting it would be to explore a shipwreck. But, if every diver who visited the wreck before you took a piece of the wreck, there would be nothing left for you to explore when you got there!

Some people, called salvagers, make their living by finding wrecks and selling treasure and other things they find on the wreck. They spend a lot of time and money to locate the a wreck and salvage items from it. Many times they find there is not anything worth taking. But, sometimes they find items that are very valuable. The law usually requires salvagers to get permission from the government and to make a complete study of the wreck before they can remove anything. People who break these laws and take items they shouldn't are modern-day pirates!