Ocean Exploration Timeline Title

1801 - 1900



U.S. Coast Survey Established

President Thomas Jefferson signs a law establishing the United States Coast Survey. The organization studies the eastern coast of the United States and returns data about a wide range of maritime subjects including tides and tidal currents, sea floor characteristics, and the depth and physical features of near-shore waters.



First use of Scuba

Englishman William H. James designs a self-contained underwater breathing apparatus, or scuba. In James' design, the diver wears a helmet and carries a supply of compressed air in a cast-iron belt fastened around the waist. This device allows the diver to remain underwater for up to an hour.


December 27, 1831

Voyage of the H.M.S. Beagle

English naturalist Charles Darwin departs England aboard the H.M.S. Beagle. The goal of the expedition is to perform a survey of Patagonia and Tierra del Fuego. Darwin studies the plants and animals at each new stop. He discovers many unique species on the Galapagos Islands off the coast of Peru in South America. These discoveries lead to his groundbreaking theory of evolution. In his book, The Origin of Species, Darwin suggests that the deep ocean may be a sanctuary for living fossils.


First Practical Diving Suit

Augustus Siebe, a German instrument maker, refines and improves previous diving suit designs and introduces the "Siebe Improved Diving Dress". This diving suit is the true predecessor to the famous deep-sea diving suit familiar to everybody today. The improved design allowed a greater freedom of movement for the diver and would be used for over a century.


January 3, 1840

First Modern Sounding

Sir James Clark Ross conducts the first open ocean deep-water sounding in 2425 fathoms (14,450 feet) in the south Atlantic ocean at at Latitude 27 S Longitude 17 W. The sounding is taken using the traditional method of lowering a hemp rope over the side of the ship.


Darwin on Coral Reef Atolls

Charles Darwin publishes The Structure and Distribution of Coral Reefs. In this work he discusses how coral atolls are formed from the subsidence and erosion of volcanic islands.


Speculation on Deep Sea Life

British naturalist Edward Forbes states his belief that life cannot exist below 300 fathoms (1800 feet) in the deep sea. This declaration begins a 20-year debate about the possible existence of a lifeless zone in the ocean known as an azoic zone.


Continental Shelf

Coast Survey soundings in support of Gulf Stream investigations result in the discovery of the continental shelf break and the continental slope.



Discovery of Deep Sea Life

Edward Forbes' theory of on deep sea life is called into question when Louis F. de Pourtales of the U.S. Coast Survey examines Coast Survey sounding operations that find indications of life in depths over 1000 fathoms (6000 feet).


First Deep Sea Canyon Discovered

James Alden, commanding officer of the Coast Survey Steamer Active, discovers a deep submarine valley, or "gulch," in the center of Monterey Bay off the coast of California. Alden had discovered the first known deep sea canyon, now known as Monterey Canyon. This canyon extends 95 miles into the Pacific Ocean and reaches a depth of 11,800 feet.



First Chart of the Gulf Stream

The first chart of the Gulf Stream is published by the U.S. Coast Survey. The Gulf Stream is a warm ocean current that originates in the Gulf of Mexico and travels up the eastern coast of the North America, where it brings warmer climate to the northern regions of the Atlantic Ocean. The current can have a significant impact on ships traveling in the area.


First U.S. Navy Submarine

The United States Navy contracts French emigrant Brutus de Villeroi to design a submarine. The vessel is built by the firm of Neafie & Levy and is made of iron with small circular plates of glass on top for light. Known as the Alligator, the sub is powered by sixteen hand-powered paddles protruding from the sides. It was built for use in the Civil War, but was never used in battle.


Proof of Deep Sea Life

American naturalist Louis F. de Pourtales conducts dredging operations from the Coast Survey Steamers Corwin and Bibb off the southern coast of Florida. During the operation, he finds prolific life extending below 300 fathoms (1800 feet).


Deep Sea Life in Abundance

Scottish naturalist Charles Wyville Thomson dredges the ocean floor from the HMS Lightning and Porcupine and discovers life as deep as 2,400 fathoms (14,400 feet, 4,389 meters). This evidence finally disproves Edward Forbes' theory of a lifeless (azoic) zone below 300 fathoms (1,800 feet, 548 meters).



Early Marine Survey of the Americas

Swiss naturalist Louis Agassiz takes the steamship Hassler on a biological survey of the Americas. The expedition begins on the East Coast of the United States and continues south through the Straits of Megellan and on to San Francisco. The ship is outfitted for deep ocean sounding and dredging. More than 30,000 specimens of marine life are collected and cataloged.


First Wireline Sounding

Irish physicist and engineer Sir William Thomson invents an operational wireline sounding machine. Modifications of this machine ultimately replace the traditional hemp-rope sounding methods. The new wireline machines are faster and more accurate, making it much easier for researchers to survey the ocean depths.

December 21, 1872

Voyage of the H.M.S. Challenger

Intrigued by the earlier work by Charles Darwin aboard the Beagle, the H.M.S. Challenger sails from Portsmouth, England and begins a four-year around the world. During the voyage, scientists test the salinity, temperature and density of the seawater. Information is also collected about ocean currents, sediment, and meteorology. The crew discovers underwater mountain chains and hundreds of species previously unknown. This research is eventually consolidated into a fifty-volume research report known as The Challenger Report. This research forms the basis of modern oceanography.


Sigsbee Sounding Machine

Commander Charles D. Sigsbee commands the Coast Survey Steamer Blake, where he modifies the Thomson Sounding Machine. His improved instrument is termed the Sigsbee Sounding Machine. This new machine becomes the basic model for wireline sounding in the deep sea for the next 50 years.



First Oceanographic Research Vessel

The U.S. Fisheries Commission Steamer Albatross begins operations. The Albatross is the first vessel built by any government for the sole purpose of oceanographic research. This iron-hulled, twin-screw steamer would conduct serious marine research for nearly 40 years until it is finally decommissioned in 1921.


First Modern Electric Submarine

The French Navy launches the Gymnote. It is the first electrically powered and fully functional military submarine. The steel-hulled craft is powered by a 204-cell battery. It completes over 2,000 successful dives before being scrapped for its limited range.



Marine Survey of the Pacific

Swiss Zoologist Alexander Agassiz makes several expeditions on the steamship Albatross to study coral reefs in the Pacific Ocean. The ship's crew makes soundings and collects specimens from islands and atolls in the South Pacific. Over the next six years, the expeditions discover an abundant range of marine life from previously unexplored remote regions.