Early Diving Equipment

The history of diving with equipment is long and complex, and in the early stages it is mixed with legend. The exploits of Jonah are described with conviction in one text, but there is a shortage of supporting evidence. Further reference is made to him later, on the technicality that he was more a submariner than a diver. Because his descent was involuntary, Jonah was at best a reluctant pioneer diver. The history of submarine escape, when the submariner may become a diver, is discussed in Chapter 64.

Some claim that Alexander the Great descended in a diving bell during the third century BC. Details of the event are vague, and some of the fish stories attributed to him were spectacular. One fish was said to have taken 3 days to swim past him! It is most unlikely that the artisans of the time could make glass as depicted in most of the illustrations of the ‘event’. This may have been a product of artistic licence or evidence that the incident is based more in fable than in fact.

Snorkels, breathing tubes made from reeds and bamboo (now plastic, rubber or silicone), were developed in many parts of the world. They allow a diver to breathe with the head underwater. Aristotle inferred that the Greeks used them. Columbus reported that the North American Indians would swim toward wild fowl while breathing through a reed and keeping their bodies submerged. They were able to capture the birds with nets, spears or even their bare hands. The Australian aborigines used a similar approach to hunt wild duck. Various people have ‘invented’ long hose snorkels. The one designed by Vegetius, dated 1511, blocked the diver’s vision and imposed impossible loads on the breathing muscles.

Some have interpreted an Assyrian drawing dated 900 BC as an early diving set. The drawing shows a man with a tube in his mouth. The tube is connected to some sort of bladder or bag. It is more likely a float or life jacket. The tube length was a metre or more and so impossible to breathe through.

Leonardo da Vinci sketched diving sets and fins. One set was really a snorkel that had the disadvantage of a large dead space. Another of his ideas was for the diver to have a ‘wine skin to contain the breath’. This was probably the first recorded design of a self-contained breathing apparatus. His drawings appear tentative, so it is probably safe to assume that there was no practical diving equipment in Europe at that time.

Another Italian, Borelli, in 1680, realized that Leonardo was in error and that the diver’s air would have to be purified before he breathed it again. Borelli suggested that the air could be purified and breathed again by passing it through a copper tube cooled by sea water. With this concept, he had the basic idea of a rebreathing set. It could also be claimed that he had the basis of the experimental cryogenic diving set in which gas is carried in liquid form and purified by freezing out carbon dioxide.

Diving bells were the first successful method of increasing endurance underwater, apart from snorkels. These consist of a weighted chamber, open at the bottom, in which one or more people could be lowered under water. The early use of bells was limited to short periods in shallow water. Later, a method of supplying fresh air was developed. The first fully documented use of diving bells dates from the sixteenth century.

In 1691, Edmond Halley, the English astronomer who predicted the orbit of the comet that bears his name, patented a diving bell that was supplied with air in barrels (Figure 1.1). With this development diving bells became more widespread. They were used for salvage, treasure recovery and general construction work. Halley’s bell was supplied with air from weighted barrels, which were hauled from the surface. Dives to 20 metres for up to 1 1/2 hours were recorded. Halley also devised a method of supplying air to a diver from a hose connected to the bell. The length of hose restricted the diver to the area close to the bell. It is not known whether this was successful. Halley was one of the earliest recorded sufferers of middle ear barotrauma.

Swedish divers had devised a small bell, occupied by one person and with no air supply to it. Between 1659 and 1665, 50 bronze cannons, each weighing more than 1000 kg, were salvaged from the Vasa. This Swedish warship had sunk in 30 metres of water in Stockholm harbour.

Figure:Edmond Halley’s diving bell, 1691. The weighted barrels of air that were used to replenish the air can be clearly seen.

The guns were recovered by divers working from a bell, assisted by ropes from the surface. This task would not be easy for divers, even with the best of modern equipment.

Breath-Hold Diving

The origins of breath-hold diving are lost in time. Archaeologists claim that the Neanderthal human, an extinct primitive human, dived for food, likely in the first instance gathering shellfish by wading at low tide before diving from canoes. By 4500 BC, underwater exploration had advanced from the first timid dive to an industry that supplied the community with shells, food and pearls.

From the ancient Greek civilization until today, fishers have dived for sponges, which, in earlier days, were used by soldiers as water canteens and wound dressings, as well as for washing.

Breath-hold diving for sponges continued until the nineteenth century when helmet diving equipment was introduced, allowing the intrepid to gamble their lives in order to reach the deeper sponge beds. Greek divers still search the waters of the Mediterranean Sea as far afield as northern Africa for sponges.

The ancient Greeks laid down the first rules on the legal rights of divers in relation to salvaged goods. The diver’s share of the cargo was increased with depth. Many divers would prefer this arrangement to that offered by modern governments and diving companies.

In other parts of the world, industries involving breath-hold diving persist, to some extent, to this time. Notable examples include the Ama, or diving women of Japan and Korea, and the pearl divers of the Tuamoto Archipelago.

The Ama has existed as a group for more than 2000 years. Originally the male divers were fishermen, and the women collected shells and plants. The shells and seaweed are a prized part of Korean and Japanese cuisine. In more recent times, diving has been restricted to the women, with the men serving as tenders. Some attribute the change in pattern to better endurance of the women in cold water. Others pay homage to the folklore that diving reduces the virility of men, a point many divers seem keen to disprove.

There is a long history of the use of divers for strategic purposes. Divers were involved in operations during the Trojan Wars from 1194 to 1184 BC. They sabotaged enemy ships by boring holes in the hull or cutting the anchor ropes. Divers were also used to construct underwater defences designed to protect ports from the attacking fleets. The attackers in their turn used divers to remove the obstructions.

By Roman times, precautions were being taken against divers. Anchor cables were made of iron chain to make them difficult to cut, and special guards with diving experience were used to protect the fleet against underwater attackers.

An interesting early report indicated that some Roman divers were also involved in Mark Anthony’s attempt to capture the heart of Cleopatra. Mark Antony participated in a fishing contest held in Cleopatra’s presence and attempted to improve his standing by having his divers ensure a constant supply of fish on his line. The Queen showed her displeasure by having one of her divers fasten a salted fish to his hook.
Marco Polo and other travellers to India and Sri Lanka observed pearl diving on the Coromandel Coast. They reported that the most diving was to depths of 10 to 15 metres, but that the divers could reach 27 metres by using a weight on a rope to assist descent. They carried a net to put the oysters in and, when they wished to surface, were assisted by an attendant who hauled on a rope attached to the net. The divers were noted to hold their nose during descent.

The most skilled of the American native divers came from Margarita Island. Travellers who observed them during the sixteenth, seventeenth and eighteenth centuries reported that these divers could descend to 30 metres and remain submerged for 15 minutes. They could dive from sunrise to sunset, 7 days a week and attributed their endurance to tobacco! They also claimed to possess a secret chemical that they rubbed over their bodies to repel sharks. The Spaniards exploited these native divers for pearling, salvage and smuggling goods past customs. The demand for divers was indicated by their value on the slave market, fetching prices up to 150 gold pieces.

Free diving appears to have evolved as a modern sport in the mid-1940s, initially as a competition among Italian spearfishers. Currently the sport, which is steadily gaining popularity, encompasses a variety of disciplines. These include the following:

In ‘no limits’, a diver can use any means to travel down and up the line, as long as the line is used to measure the distance. Most divers descend down a line using a weighted sled and return to the surface aided by an inflatable balloon. Officially recorded depths in excess of 210 metres have been achieved using this method.

‘Constant weight apnoea’ diving is where descent and ascent occur along a line, although the diver is not permitted to pull on this line to assist movement. No weights can be removed during the dive. Mono-fins or bi-fins can be used.

‘Constant weight without fins’ is the same as constant weight apnoea but without the use of fins.

With ‘variable weights’, the diver again descends with the aid of a weighted sled, but this weight is limited. Ascent is achieved by finning or pulling up the cable, or both.
‘Free immersion’, which emerged in places where equipment was difficult to obtain, involves a finless diver (with optional suit, mask or weights) who pulls himself or herself down and then up a weighted line.

‘Static apnoea’ involves resting breath-holding (usually lying in a pool) with the face submerged. Officially recorded times in excess of 11 minutes have been achieved using this method.

‘Dynamic apnoea’ measures the distance covered in a pool during a single breath-hold.