1715 - John Lethbridge built a "diving engine", an underwater oak cylinder that was surface-supplied with compressed air. Water was kept out of the suit by means of greased leather cuffs, which sealed around the operator's arms.

1776 - First authenticated attack by military submarine - American Turtle vs. HMS Eagle, New York harbor.

1788 - John Smeaton refined the diving bell by incorporating an efficient hand-operated pump to supply fresh compressed air and a non-return valve to keep air from going back up the hose when pumping stops.

1824 - Charles Anthony Deane patented a "smoke helmet" for fire fighters. This helmet was used for diving, too. The helmet fitted over the head and was held on with weights. Air was supplied from the surface.

1828 - Charles Deane and his brother John marketed the helmet with a "diving suit." The suit was not attached to the helmet, but secured with straps.

1837 - Augustus Siebe produced the first diving helmet and dress, based on Edwards' design. The young and clever engineer George Edwards, after using the Deane gear for over a year, he suggested safety improvements.

1840 - Seibe's helmet was used by the Royal Navy on salvage operations of the wreck of the Royal George. The diving team, lead by Colonel Pasley, was very satisfied with Siebe's helmet. The "Siebe Improved Diving Dress" is adopted as the standard diving dress by the Royal Engineers. Pasley too suggested some improvements to the helmet. He suggested to seperate the bonnet and the breastplate by means of an interrupted thread facility. Siebe took over the advice and thus the basic design for all later diving helmets was born.

1843 - The first diving school was established by the Royal Navy.

1865 - Benoit Rouquayrol and Auguste Denayrouse patented an apparatus for underwater breathing. It consisted of a horizontal steel tank of compressed air on a diver's back, connected to a valve arranged to a mouth-piece. With this apparatus the diver was tethered to the surface by a hose that pumped fresh air into the low pressure tank, but he was able to disconnect the tether and dive with just the tank on his back for a few minutes.

1876 - Englishman Henry A. Fleuss developed the first workable, self-contained diving rig that used compressed oxygen.

1878 - Paul Bert published "La Pression Barometrique," a book length work containing his physiologic studies of pressure changes.

1908 - John Scott Haldane, Arthur E. Boycott and Guybon C. Damant, published "The Prevention of Compressed-Air Illness," a paper on decompression sickness.

1909 - The Draeger company of Lübeck, Germany a manufacturer of gas valves, firefighting equipment, and mine safety devices plunges into making dive gear. The company creates a self-contained dive system combining a "hard hat" style helmet with a backpack containing compressed oxygen. Over the next few years, Draeger will win numerous patents for diving equipment.

1910 - Dr. John Scott Haldane, a British physiologist, confirms that caisson disease is caused by the release of dissolved nitrogen when surfacing. To enable divers to avoid "the bends," Haldane develops a procedure that calls for gradually staged "decompression." His pioneering research culminates in publication of the first dive tables.

1910 - Sir Robert Davis, a director of Siebe, Gorman, refines the Fleuss system and comes up with the Davis False Lung. His reliable, compact, easily stored, and fully self-contained rebreather is adopted (or copied) throughout the world for use as an emergency escape device for submarine crews.

1912 - Germany's Westfalia Maschinenfabrik markets a hybrid dive system that blends scuba and surface-fed components with mixed gas technology.

1915 - An early film of 20,000 Leagues Under the Sea marks the first commercial use of underwater cinematography. Cast and crew use modified Fleuss/Davis rebreathers and "Oxylite," a compound that generates oxygen through a chemical reaction. (Oxylite explodes if it gets wet, a trait that tends to limit its popularity as a scuba component.)

1917 - The U.S. Bureau of Construction & Repair introduced the Mark V Diving Helmet. It was used for most salvage work during World War II. The Mark V Diving Helmet became the standard U.S. Navy Diving equipment.

1924 - First helium-oxygen experimental dives were conducted by U.S. Navy and Bureau of Mines.

1930s - Guy Gilpatric pioneered the use of rubber goggles with glass lenses for skin diving. By the mid-1930s, face masks, fins, and snorkels were in common use. Fins were patented by Louis de Corlieu in 1933.

1930 - William Beebe descended 1,426 feet in a bathysphere attached to a barge by a steel cable to the mother ship.

1933 - Yves Le Prieur modified the Rouquayrol-Denayrouse invention by combining a demand valve with a high pressure air tank to give the diver complete freedom from hoses and lines.

1934 - William Beebe and Otis Barton descended 3,028 feet in a bathysphere.