Renaissance diving equipment

1500s: Leonardo Da Vinci designs several diving devices consisting mainly of breathing tubes connected to a facemask and to a float at the other end. Later attempts on constructing breathing apparatuses were based on his sketches.

The Enlightenment Era

The diving bell was the dominant diving device for the next centuries.

1616: Franz Kessler designs a diving bell. The bell was negatively buoyant so the diver could walk on the sea floor. The diver sat on an internal framework and the body of the bell was equipped with several small eye ports from where he looked through.

1640:  Hans Albrecht von Treileben and Anders Peckel uses a primitive diving bell to salvage 42 cannons from the Swedish ship Vasa at a depth of ca. 30 metres.

1680: Giovanni Borelli, an Italian mathematician develops a rebreathing diving set. He believed that by recirculating the exhaled gas through copper tube cooled by seawater would purify it. He also experimented with fin and buoyancy compensating devices. Now the diver became more an underwater swimmer, than a sea bottom walker. His device was probably never tested, but it depicts an early version of a rebreather set (SCUBA), as well the use of fins. 

1690: Edmund Halley develops a diving bell. In 1716 this design was redeveloped by the use of air-filled barrels to replenish the air supply.

1715: Lethbridge designs a diving device looking like a cylindrical barrel, which accommodated the diver, whose arms protruded through tightly sealed sleeves.

1788: John Smeaton, constructs the first modern diving bell. The structure was made of cast iron, and it was supplied with constant airflow provided from a hand-operated pump on the surface.

 1834:  William H. James designs a self-contained underwater breathing apparatus (SCUBA). The diver was wearing a helmet with compressed air flow in its interior. The air reservoir was fastened around the waist of the diver. According to James, the diver could stay underwater for as long as an hour using this outfit. 

1837: Augustus Siebe introduces the standard diving dress with copper hel­met and leaden weights, rubberized canvas suit and leaden shoes. The ‘standard hard hat’ is fed through a safe air pump operated by two individuals. The Deane brothers used this equipment in salvage operations around Britain. Simultaneously, similarly designed equip­ment was developed elsewhere, but worldwide the Siebe Gorman standard diving dress-and its versions-were the most successful. This outfit was used for diving operations until the last quarter of the 20^th century.

1854:  The first important example of an archaeological application where a tube supplied air to a diver, was the device that Count Adolphe von Morlot used near Morges in his settlement research in Lake Geneva. A hose, into which air was pumped through a very simple pump from the surface, was connected to a diving cap, similar to a ‘helmet’, closing around the diver’s head.

Understanding physiological limits

1878: Paul Bert publishes “La Pression Barometrique”.  Not only did he demonstrate that nitrogen bubbles cause decompression sickness but he also recognised the existence of “silent bubbles” following decompression. He also described the acute toxic central nervous system effects of oxygen.

1908: JS Haldane, Boycott and Damant publish “The Prevention of Compressed Air Illness”. They recommended staged decompression.

 1915: The United States Navy (USN) Diving Tables is first published. Stillson and French conducted experimental research based on the original Haldane tables.

 1926: A French Naval officer, Yves Le Prieur, patents the Frenez-Le-Prieur self contained diving apparatus. It was a diving set that had a cylinder of compressed air with a hand-regulated valve in­stead of a demand-valve. It fed a free flow of air into a mouthpiece or a full-face mask and was used with some success.

 1943 Emile Gagnan, an engineer, and J Cousteau design the “aqua lung”.  It contained a demand valve to regulate the air supply when the ambient pressure varies underwater.

 1959: YMCA SCUBA Program is the first US organized course for scuba certification. Approximately 7 million divers are active worldwide and 500,000 more are training every year.

 2005: Nuno Gomes uses self-contained underwater breathing apparatus (SCUBA) to dive to a depth of 318.25 metres. This is mankind’s deepest open water dive, until now, according to the official current world deep dive records.

 2007:  Free diver (breath hold diver) Herbert Nitsch dives to over 214 metres on a “No Limits” free dive in Greece. This became a world free diving  record in the “No Limits” category. On June, 2012, in Santorini, Greece, he surpassed his own record, with a “No Limit” dive to 253.2 metres, but suffered from decompression sickness.

Mixed gas and saturation systems – Prolonged underwater stays

 1964: The first larger habitat, SEALAB, is launched. The lab is put at a depth of 58 meters. The four saturation divers were called ‘aquanauts’. The aquanauts lived in SEALAB for 11 days, breathing a mixture of Helium and Oxygen, which becomes the standard for deep diving as HELIOX. Other missions including under water habitats were to follow later.

1966: Commercial saturation diving systems were quickly adopted by companies specializing in offshore in­dustry and technology. In 1966 the first saturation dive was done in the Gulf of Mexico using a system designed by Westinghouse Electric Corporation, Un­derseas Division (Tom O’Neill and Alan Krassburg).

1992: Comex, a leading company in diving systems and technology, begins the HYDRA 11 proj­ect, including decompression chamber experiments. Teo Mavrostomos made a simulated dive to 2300ft (701m), which was a success and lasted 42 days. This was the deepest experimental human dive carried out so far and the main breathing gas mixtures were heliox and hydreliox (exotic breathing gas mixture of helium, oxygen and hydrogen).

Present: Diving companies, research facilities and Universi­ties are intrigued by the saturation diving technol­ogy and new boundaries have been established. Research on diving medicine and physiology carries on constantly. Currently, the main underwater habitat devoted to science is the Aquarius Reef Base, which is located in the  Florida Keys National Marine Sanctuary at a depth of ca. 20 metres. NASA, regularly, sends team of astronauts, engineers, technicians, and scientists for the NASA Extreme Environment Mission Operations (NEEMO) program. Main objective of the program is to conduct tests and research related to future asteroid exploration activities.