The Club des Scaphandres et de la Vie sous l’Eau which I founded with Commandant Le Prieur in late summer 1935 lists the following main aims in its statutes:
1. The popularization of subaquatic exploration methods, either by individuals or groups;
2. The development of all related activities;
3. The organisation of all types of subaquatic sports and other events;
4. The implementation of inventions to serve these aims.
This is a far-reaching programme, which is already justifying itself through its importance for rescuers in the frequent cases of drowning accidents happening between depths of 0 and 5 metres, and also as regards sports and science, both of which will certainly develop as the potential of the Club increases. Indeed, enthusiasts now have the necessary equipment available to them for safe and easy diving.
The art of diving without any aid apart from holding one’s breath is several millennia old. Four thousand years ago the Chinese fished for pearls, and the Rhodians had a law which gave a proportional part of what was found in the sea back to the depths from which they came. Even diving with apparatus is an old activity, either using a tube with one end opening above the surface of the water – this simple system only enables the diver to submerge immediately below the surface and does not counter the pressure – or using a diving-bell, as mentioned by Aristotle. Celebrated dives lasting several days and nights have also been attributed to Alexander the Great. From the sixteenth century onwards, diving apparatus increased.
Currently, diving suits are of three types:
a) A watertight helmet for the head, supplied with compressed air by a pump requiring two men;
b) The same, but with a self-contained air supply, the oxygen being regenerated by certain products;
(These two types are usually attached to a complete suit with lead weights of between 2 and 8 kilos on the chest and boots);
c) A completely metallic diving suit which does not allow leg or arm movement and which resists water pressure; this is supplied with air at normal pressure. This final model has enabled people to reach depths of 140 metres; (the water pressure only allows the use of ball and socket joints holding cutting or slicing instruments - the diver becomes a sort of robot).
Without the protection which metal, for example, can offer from external pressure, it is not possible to dive beyond twenty metres: we are subjected to about three kilos per square centimetre, which is uncomfortable on the eardrum for one thing. (Atmospheric pressure increases by one kilo for every ten metres of depth.) William Beebe’s metallic sphere protecting its occupants from external pressure reached a depth of 900 metres.
The simplest piece of apparatus, devised by Commandant Le Prieur, takes the form of a watertight rubber mask held over the face by adjustable straps; the mask has a window at the front which gives great visibility, and the folds of the rubber prevent the window from crushing the face when the pressure increases, which does not happen with goggle masks. Air is supplied through a pipe connected to the surface with either a hand-operated pressure pump or foot pump controlled by someone at the surface, or a mechanical pump, or indeed a 3-litre bottle of air compressed to 150 kilos. In the former case, the diver uses a lead belt as a ballast, and in the latter, the 8-kilo bottle is ballast enough to allow the diver to move around very easily in the water with a simple movement: the weight no longer exists.
In order to combat the pressure, more or less air is given depending on the depth of the dive. Down to a depth of four or five metres, the bottle can last for between quarter of an hour and twenty minutes: in order to dive deeper, a larger bottle is needed. This is in addition to the fact that with a depth of five metres or more the diver requires more air to be able to descend and in particular return to the surface again slowly to prevent the problems resulting from pressure differences.
As always with a previously unexplored area, this subject has seen the silliest flights of fancy. Here are two examples:
On 24th August 1834, the American Daily Times newspaper wrote: the oxygen breathed in by deep-sea divers greatly increases their strength. At a depth of 30 metres, a diver could bend an iron bar. At 35 metres, two divers came to blows. In the grip of rage and great quantities of oxygen, one diver broke the mask of the other, and he was brought back up to the surface dead.
Also, several years ago, a film by the Williamsons was shown: they had filmed footage for this film underwater by using a wide tube with portholes which they pushed straight down. The resulting film was a mixture of low-quality pictures taken directly underwater, faked pictures and much clearer pictures filmed in an aquarium. The ingenuous audience were tricked by a story of an octopus, during which they could either see nothing at all, or they could see the diver and the octopus, but not both at the same time. A rapid montage and the audience’s ignorance made this a successful bluff. The film was shown again recently, this time with sound, and “enhanced” by a dreadful commentary by a “technician” affiliated to the Natural History Museum.
The view underwater is very different from our usual perception, both as regards light and aspect (since we normally see underwater from above, whereas in diving we can see things in profile), to the extent that the most minor thing - something which were it seen from the surface would not attract our attention - takes on an extraordinary and magical appearance when we are underwater. And gradually, as we grow accustomed to it, we become part of the underwater world, since sea creatures are not disturbed at all by a human presence provided there is not too much movement from it.
Unfortunately it is only possible to practise such diving in our coastal waters in a couple of summer months, in the Mediterranean and the Bay of Biscay: since the diver cannot make such energetic movements as he can on the surface and is totally compressed in a mass which gets colder the deeper he goes, it is necessary to wear a heated suit, such as the one which Commandant Le Prieur has just developed which will make diving possible regardless of the season or the location, while allowing diving enthusiasts the necessary movement.
This is really essential: can we imagine any other sport which becomes impossible because of a 15° fluctuation in temperature? Diving is a sport in itself and can lead to underwater versions of many sports normally practised on the surface – including fishing and hunting! For example, with an electrical switch, Beebe can release a pellet of fulminate from the explosive end of a 2-metre fishing rod positioned near the fish he wants to capture in order to stun or kill it. Commandant Le Prieur has developed rifles, including a pneumatic one, which has a canister allowing ten shots and a little harpoon which is reloaded every time; the harpoon travels several metres before being slowed down by the water, and during this short journey can pierce fairly large prey. Monsieur Suter, wearing the Miller Dunn apparatus, a helmet placed simply over the head and supplied with air through a hand-operated pump, sits underwater with a very short fishing rod with a rubber ‘maggot’ hanging from it which he only needs to wave under the nose of the big fish, and with which he taps the little ones on the nose to make them flee when they come and try to hook themselves on the maggot.
Sunlight can only penetrate the water by diffusion when the sun is at 30° to either side of the vertical, the angle of total reflection, and of course the light must be able to penetrate directly into the water to a certain extent in order to take photographs. Similarly, if the surface of the water is disturbed, the light will be too fragmented, even if there is a sufficient amount, to give results which are anything other than strange. We know now that after passing through an intense twilight blue, light fades away at a depth of between 500 and 600 metres. But well before this depth, there is not enough light to expose photographic plates or to allow aquatic flora to grow.
Of course, at the depths we are talking about here, we can always rely on the light. The smaller the photographic (or cinematographic) format used, the greater the amount of light that will be condensed for the same shot. There is an advantage therefore in using reduced formats which can always be enlarged when they are projected; the limits of this enlargement depends on the grain of the film, but the grain is becoming finer and finer as the technique is developed, and besides, film enthusiasts do not tend to screen their films to large audiences in large theatres requiring powerful enlargement.
There is another advantage in filming in reduced format, and this is that, all conditions being otherwise equal, the focal point of the lens will be shorter, which gives a closer infinity point. Reduced format (16mm, 9.5 mm and 8mm) will therefore always have enough light and will always be in focus. The same is not true for professional format (35mm in cinema); the photographer has a difficult job because to obtain photographs of the quality possible in an aquarium it is necessary to adjust the focus constantly and use 8000 watts of light for every cubic metre of water… This can only be achieved by installing sources of electricity underwater, and these are tricky to insulate and heat, and can disturb the sea creatures.
These creatures (except for seahorses – fish which are too slow and majestic to flee) will be thrown into panic by the excessive light. Even assuming that we have sufficient light and that it can be easily controlled and focused, there remains the question of focusing the camera; this is almost impossible to do when the camera is submerged; rather it has to be set to a given focus beforehand.
So how do we take these shots?
In order to stir up the desire to dive as well as to film, we can start by using a simple periscopic box (with two mirrors at 45°, one below the water level and the other above). A camera placed behind the mirror which is above the water will see everything happening underwater just as if it were itself submerged. Just like with a camera looking through a glass box forming the bottom of a boat, we can adjust the camera out of the water and focus it easily. But then, when we get more demanding and want to dive with the camera, it has to be encased in a watertight box with a window in front of the lens and a shade to eliminate the shimmer of diffused light. Rubber gloves hermetically seal holes which have been cut in the box to allow access to the essential camera controls. A thick foam rubber provides a waterproof seal between two metal plates so that sea water or chlorine in swimming pools, or water in general, cannot corrode the equipment. In order to remove the camera, or put it back in, you lift the shutter plate after removing thes bolts from the seal.
It is still not possible to focus the lens when the camera is submerged – it has to be focused on dry land, taking account of the fact that objects underwater appear a certain proportion closer both to the eye and the lens, and seem for example to be 2m 20 away when in reality they are 3m away. But once we are familiar with this law, we can really begin to control underwater photography.
Jean Painlevé, "Vivre sous l'eau" originally published in Marianne, 15 April 1936.