SEEING IS BELIEVING - The Evolution of the Modern Diving Mask
It would seem that, with the benefit of hindsight, something as fundamental as looking underwater with a diving mask should have been invented and perfected a long time ago.. but not so. This tool, so central to the sub-aquatic experience, did not come into its own until the 20th century, and even then did not reach its full potential until some sixty short years ago. Before this latter day development, with the exception of the incredibly tenacious but health damaging practices of pre-industrial age free divers, those who had an interest in seeing under water would have to resort to peering from the surface, using heavy, awkward pieces of equipment or relying on second hand descriptions to satisfy their visual curiosity.
The Pre-Mask Era
Historical data shows evidence of free diving in such diverse early cultures as the sponge divers of Greece, the pearl divers of the Caribbean and the Yahgan Indians of Tierra Del Fuego, to name but a few. All of these divers however, appear to have swum under water without the aid of eye coverings. While there is no questioning that they were successful, in their way, this form of diving did not come without its costs, as Robert Marx describes in his book: "The history of Underwater Exploration":
“These women dive in eight fathoms of water and more and spend the better part of 15 or 20 minutes under water. Their eyes, by continual diving, grow red as blood; whereby, a diving-woman is distinguished from all others”.
This text goes on to relate that many free divers developed a heightened ability to see underwater but at the cost of reduced vision above the surface.
From the time of the middle ages (and in some few cases earlier) Europeans had also been looking under water using a submersible device called the diving bell, developed to locate objects such as ships and salvage worthy cargo. Positioned within the air filled inverted bell, a diver could look below or out of a small view port and direct grappling machinery and even reach or swim outside to retrieve objects. While this was a surprisingly successful (but limited) way to see beneath the surface, the bell required both a tender above and labour intensive maneuvering to lower and position it near the object being sought underwater.
It would seem that, with the benefit of hindsight, something as fundamental as looking underwater with a diving mask should have been invented and perfected a long time ago.. but not so. This tool, so central to the sub-aquatic experience, did not come into its own until the 20th century, and even then did not reach its full potential until some sixty short years ago. Before this latter day development, with the exception of the incredibly tenacious but health damaging practices of pre-industrial age free divers, those who had an interest in seeing under water would have to resort to peering from the surface, using heavy, awkward pieces of equipment or relying on second hand descriptions to satisfy their visual curiosity.
The Pre-Mask Era
Historical data shows evidence of free diving in such diverse early cultures as the sponge divers of Greece, the pearl divers of the Caribbean and the Yahgan Indians of Tierra Del Fuego, to name but a few. All of these divers however, appear to have swum under water without the aid of eye coverings. While there is no questioning that they were successful, in their way, this form of diving did not come without its costs, as Robert Marx describes in his book: "The history of Underwater Exploration":
“These women dive in eight fathoms of water and more and spend the better part of 15 or 20 minutes under water. Their eyes, by continual diving, grow red as blood; whereby, a diving-woman is distinguished from all others”.
This text goes on to relate that many free divers developed a heightened ability to see underwater but at the cost of reduced vision above the surface.
From the time of the middle ages (and in some few cases earlier) Europeans had also been looking under water using a submersible device called the diving bell, developed to locate objects such as ships and salvage worthy cargo. Positioned within the air filled inverted bell, a diver could look below or out of a small view port and direct grappling machinery and even reach or swim outside to retrieve objects. While this was a surprisingly successful (but limited) way to see beneath the surface, the bell required both a tender above and labour intensive maneuvering to lower and position it near the object being sought underwater.
A step forward was the diving helmet and dress perfected by the Siebe Gorman Company in the mid 1800’s. The “hardhat” diver still needed a tender above to supply air but could now move independently in order to search and interact with the underwater environment. One could see quite well within the limitations of a bulky helmet but it, and the accompanying equipment needed, was both cumbersome and generally limited to commercial diving operations.
Those who sought a less equipment intense solution could use a simpler and older design commonly called the shallow water helmet. This design fit over the head like the commercial diving helmet but had no dress, or suit, to go with it and was open on the bottom to let the surface supplied air escape. It allowed relatively good vision for the diver, provided they did not bend too far forward and flood the helmet. The shallow water helmet, thought invented and in use for centuries beforehand, was popularized in the early 20th century by William Beebe (noted zoologist and curator of the American Museum of Natural History). Below is a quote from his book “Beneath Tropic Seas”:
"You are standing on a metal ladder in water up to your neck. Something round and heavy is slipped gently over your head, and a metal helmet rests upon your shoulders... You wave good-by to your grinning friend at the pump, and slowly descend, climbing down step by step... Only a moment passes since you left the world overhead, or was it many hours? A gentle tug comes along the hose and you resent this reminder of an existence which you had almost forgotten...
All I ask the reader is this, - Don't die without having borrowed, stolen, purchased or made a helmet of sorts, to
glimpse for yourself this new world".
As well as the above mentioned diving equipment, two very popular pre mask devices employed in earlier times for under water observation were the viewing box/bucket and the glass bottomed boat. Simple to construct, the viewing box eliminated light refraction and allowed the surface bound observer to see as far as visibility would allow. Glass bottom boats (really only boats with windows placed in the bilge) were widely used in Victorian times by lake and lagoon “tourists” of the day. Even now, such boats are used to introduce land bound viewers to the sub aquatic world.
The Proto-Mask
Predating these European designs by some centuries, prototypes of the modern mask, the goggles, were being used by many Pacific ocean free divers such as the Ama of Japan to harvest food and wealth from beneath the sea. These goggles were often made using sea or tortoise shells, polished to a degree of transparency. The invention of goggles appears to have arisen out of a natural progressive necessity for sight, with no single progenitor or point of origin. Rather, it would appear that knowledge of their use was passed among coastal groups in the course of trade and travel. Even their arrival upon the European scene, as described by Philippe Tailliez in his book “To Hidden depths” was later found by him to be predated by Vietnamese divers who, in turn, were influenced by an even earlier introduction by the Chinese:
“We pooled our ideas and efforts in the same brotherly crucible. Very curious contraptions came out of it… We concocted goggles out of car inner tubes mounted over small circular or oval glasses- Cousteau had cut out a standard model to fit all faces”.
“I profited by the occasion to… visit the skin divers who were hunting in the reefs around the edge of the lagoon. They were extremely skillful and each time emerged with a fish on the ends of their spears. I examined their goggles, to find that they were cut out of buff leather or inner tube car-tires. They surrounded the eyes and nose, over the oval glass. It was exactly what we thought we had invented ourselves in 1937 on the Cote d’Azur. I asked Tram-Khau who had taught them to cut out these goggles. He thought for a moment and told me that a few years before the war a Chinese junk from Fou Quien had called at the island to collect swallows’ nests. Its crew had dived with these masks and had taught some of the fishermen how to make them”.
By the 1930’s shallow water skin diving or “goggling” had reached European, and especially Mediterranean, shores and was popularized by Guy Gilpatric (1896–1950) in the ”Saturday Evening Post” as well as in his small book on spearfishing entitled “The Compleat Goggler” (1938). Soon, commercially produced goggles began to appear alongside homemade models. While goggles did provide clearer vision underwater, their use was limited to shallow depths because of the inability to equalize the eye pieces. Divers who ventured too deep were subjected to a painful and possibly dangerous “eye squeeze” as John Cuthill retells Gordi Moores experience in his thesis "Learning strategies of Early British Columbia Divers":
"I remember diving down once at Horseshoe Bay, off the dock. And some kid said "...How deep can you dive?" And I said "I don't know". So I jumped off and swam to the bottom... at fifty feet... and I ended up uh, with a blown eye. My eye went all red and there was blood out of my ear every night when I went to sleep."
Along with the advent of goggles for free divers, it should also be noted that early rebreather development involved the use of converted gas or aviator masks which had either single or double lenses. While the danger of an eye squeeze was not an issue with them, the diver’s vision was often distorted by the varying focus of the two lenses and use was restricted to shallow depths by the limitations of oxygen toxicity.
While goggles remained popular for some time afterward, and are still used by surface swimmers today, the move towards a better solution for underwater vision, at all depths, was dramatically spurred forward by the invention of the diving “Aqualung”.
Those who sought a less equipment intense solution could use a simpler and older design commonly called the shallow water helmet. This design fit over the head like the commercial diving helmet but had no dress, or suit, to go with it and was open on the bottom to let the surface supplied air escape. It allowed relatively good vision for the diver, provided they did not bend too far forward and flood the helmet. The shallow water helmet, thought invented and in use for centuries beforehand, was popularized in the early 20th century by William Beebe (noted zoologist and curator of the American Museum of Natural History). Below is a quote from his book “Beneath Tropic Seas”:
"You are standing on a metal ladder in water up to your neck. Something round and heavy is slipped gently over your head, and a metal helmet rests upon your shoulders... You wave good-by to your grinning friend at the pump, and slowly descend, climbing down step by step... Only a moment passes since you left the world overhead, or was it many hours? A gentle tug comes along the hose and you resent this reminder of an existence which you had almost forgotten...
All I ask the reader is this, - Don't die without having borrowed, stolen, purchased or made a helmet of sorts, to
glimpse for yourself this new world".
As well as the above mentioned diving equipment, two very popular pre mask devices employed in earlier times for under water observation were the viewing box/bucket and the glass bottomed boat. Simple to construct, the viewing box eliminated light refraction and allowed the surface bound observer to see as far as visibility would allow. Glass bottom boats (really only boats with windows placed in the bilge) were widely used in Victorian times by lake and lagoon “tourists” of the day. Even now, such boats are used to introduce land bound viewers to the sub aquatic world.
The Proto-Mask
Predating these European designs by some centuries, prototypes of the modern mask, the goggles, were being used by many Pacific ocean free divers such as the Ama of Japan to harvest food and wealth from beneath the sea. These goggles were often made using sea or tortoise shells, polished to a degree of transparency. The invention of goggles appears to have arisen out of a natural progressive necessity for sight, with no single progenitor or point of origin. Rather, it would appear that knowledge of their use was passed among coastal groups in the course of trade and travel. Even their arrival upon the European scene, as described by Philippe Tailliez in his book “To Hidden depths” was later found by him to be predated by Vietnamese divers who, in turn, were influenced by an even earlier introduction by the Chinese:
“We pooled our ideas and efforts in the same brotherly crucible. Very curious contraptions came out of it… We concocted goggles out of car inner tubes mounted over small circular or oval glasses- Cousteau had cut out a standard model to fit all faces”.
“I profited by the occasion to… visit the skin divers who were hunting in the reefs around the edge of the lagoon. They were extremely skillful and each time emerged with a fish on the ends of their spears. I examined their goggles, to find that they were cut out of buff leather or inner tube car-tires. They surrounded the eyes and nose, over the oval glass. It was exactly what we thought we had invented ourselves in 1937 on the Cote d’Azur. I asked Tram-Khau who had taught them to cut out these goggles. He thought for a moment and told me that a few years before the war a Chinese junk from Fou Quien had called at the island to collect swallows’ nests. Its crew had dived with these masks and had taught some of the fishermen how to make them”.
By the 1930’s shallow water skin diving or “goggling” had reached European, and especially Mediterranean, shores and was popularized by Guy Gilpatric (1896–1950) in the ”Saturday Evening Post” as well as in his small book on spearfishing entitled “The Compleat Goggler” (1938). Soon, commercially produced goggles began to appear alongside homemade models. While goggles did provide clearer vision underwater, their use was limited to shallow depths because of the inability to equalize the eye pieces. Divers who ventured too deep were subjected to a painful and possibly dangerous “eye squeeze” as John Cuthill retells Gordi Moores experience in his thesis "Learning strategies of Early British Columbia Divers":
"I remember diving down once at Horseshoe Bay, off the dock. And some kid said "...How deep can you dive?" And I said "I don't know". So I jumped off and swam to the bottom... at fifty feet... and I ended up uh, with a blown eye. My eye went all red and there was blood out of my ear every night when I went to sleep."
Along with the advent of goggles for free divers, it should also be noted that early rebreather development involved the use of converted gas or aviator masks which had either single or double lenses. While the danger of an eye squeeze was not an issue with them, the diver’s vision was often distorted by the varying focus of the two lenses and use was restricted to shallow depths by the limitations of oxygen toxicity.
While goggles remained popular for some time afterward, and are still used by surface swimmers today, the move towards a better solution for underwater vision, at all depths, was dramatically spurred forward by the invention of the diving “Aqualung”.
The Single Lens Mask
Single lens diving masks, originating in the early 1900’s, were initially hand made from various materials such as tire tubes, copper and coated leather for the skirt and panes of glass or transparent plastic known by such trade names as "Lucite" or "Styrine" for the lens.
To the left is an interesting example from Carlos Eyles book "The Last of the Blue Water Hunters" of an early transitional mask that uses a single lens but does not incorporate the nose within it. Mask equalization was achieved by the use of a small rubber bulb reservoir.
After the Gilpatric “Saturday Evening Post” articles, as well as articles in "National Geographic" and "Life", and particularly after the promotion of SCUBA diving by such notables as Jacques Cousteau and Hans Hass; simple, commercially produced masks began to appear. To the right is an example of an early design with plastic lens and wide rubber flange.
The first single lens masks resolved the troubling issues of double vision and eye squeeze that limited goggle use but still presented the challenge of equalizing the ears at depth. Divers attempted to accomplish this in a variety of ways.
Many learned to stretch open their Eustachian tubes by swallowing or moving their lower jaw. Others reached up into the mask while diving to pinch their noses to create back pressure, flooding and clearing the mask each time they did so, while others wore nose clips like the ones shown to the left.
Many learned to stretch open their Eustachian tubes by swallowing or moving their lower jaw. Others reached up into the mask while diving to pinch their noses to create back pressure, flooding and clearing the mask each time they did so, while others wore nose clips like the ones shown to the left.
Some inventive divers began to modify the mask by gluing a rubber or cork block to the inside, near the nostrils, so that the nose could be pushed against it for ear clearing and a few commercial models, such as the Swimaster
Wide View mask to the right, eventually came with neoprene inserts for this purpose.
The Equaliz(able) Mask
The breakthrough for equalizing ears came when indents, or finger pockets, were molded into the rubber skirt of the mask near the nose so that the diver could grasp their nostrils and pinch, thus creating back pressure while avoiding a mask flood. The first equalizing mask appeared in the U.S. Divers catalog in 1959 under the model name Aqua-Pressure.
Soon, most manufacturers had equalizing masks utilizing this basic design principle available in their product line. To the left are a few examples of equalizing masks.
The breakthrough for equalizing ears came when indents, or finger pockets, were molded into the rubber skirt of the mask near the nose so that the diver could grasp their nostrils and pinch, thus creating back pressure while avoiding a mask flood. The first equalizing mask appeared in the U.S. Divers catalog in 1959 under the model name Aqua-Pressure.
Soon, most manufacturers had equalizing masks utilizing this basic design principle available in their product line. To the left are a few examples of equalizing masks.
The Purg(able) Mask
Another evolutionary development that was quite common for decades but has fallen by the way side in recent years was the inclusion of a purge valve near the nose for clearing water from the mask. To the left are a few masks of this design.
The first example of this adaptation appeared in the U.S. Divers catalog in 1962 using the model name Equi-Purge .
Most designs incorporated a simple one way mushroom valve over an orifice similar to that used by many purging snorkels and, just like the snorkel, the mechanism eventually proved to be unnecessary. To the right are some examples of purge valve equipped masks.
For many years divers could choose to use one of two techniques for mask clearing: either cracking the lower mask/face seal on a non-purge mask and exhaling, or exhaling through a purge valve equipped mask.
With the lessening of mask volumes and the complexity and failure potential of purge valves, the first method eventually won out as the preferred design option.
The first example of this adaptation appeared in the U.S. Divers catalog in 1962 using the model name Equi-Purge .
Most designs incorporated a simple one way mushroom valve over an orifice similar to that used by many purging snorkels and, just like the snorkel, the mechanism eventually proved to be unnecessary. To the right are some examples of purge valve equipped masks.
For many years divers could choose to use one of two techniques for mask clearing: either cracking the lower mask/face seal on a non-purge mask and exhaling, or exhaling through a purge valve equipped mask.
With the lessening of mask volumes and the complexity and failure potential of purge valves, the first method eventually won out as the preferred design option.
Widening the Range of Vision
A problem encountered with early mask design, and still a key marketing feature today, was how to enlarge the field of vision for the diver. The original Squale style mask had a small oval of glass set inches from the dives eyes by a stiff rubber skirt, creating a visual “tunnel” effect that limited side viewing. Most of the early efforts therefore, were focused on increasing horizontal, or peripheral vision. Some initial ideas to address this short coming revolved around using larger panes of glass, adding glass to the sides and even bending the glass to provide a panoramic effect. While the large single pane idea proved impractical early on, some methods such as multiple panes continue to be used today.
To the left are some attempts to widen the range of vision in masks:
To the left are some attempts to widen the range of vision in masks:
Lowering the Volume
Much of the issue surrounding the diver’s horizontal field of vision resolved itself once the interior volume of the diving mask was reduced. The biggest design feature to facilitate this was moving the nose pocket outside of the glass viewing frame thus changing the oval shape of the mask. From the 1950’s to the 1970’s, little concern was paid to the interior air space a mask created next to the face as it was easy enough to equalize using SCUBA, but deeper, competitive free diving made demands that could not be met by large volume designs and eventually the benefits of lower volume masks crossed over into SCUBA as well.
Much of the issue surrounding the diver’s horizontal field of vision resolved itself once the interior volume of the diving mask was reduced. The biggest design feature to facilitate this was moving the nose pocket outside of the glass viewing frame thus changing the oval shape of the mask. From the 1950’s to the 1970’s, little concern was paid to the interior air space a mask created next to the face as it was easy enough to equalize using SCUBA, but deeper, competitive free diving made demands that could not be met by large volume designs and eventually the benefits of lower volume masks crossed over into SCUBA as well.
Free diving causes the air trapped in the lungs, airway, mouth, nose and mask to compress and, as greater depths were being achieved, divers could no longer exhale enough to equalize traditional high volume masks.
Free diving masks were molded to fit closer to the face, reducing the interior air space and as a result were easier to equalize. Reducing the skirt depth of the mask also brought the glass closer to the eyes and dramatically increased the peripheral field of vision.
To the right is a comparison between a modern, low volume mask and it’s older, high volume predecessor.
Free diving masks were molded to fit closer to the face, reducing the interior air space and as a result were easier to equalize. Reducing the skirt depth of the mask also brought the glass closer to the eyes and dramatically increased the peripheral field of vision.
To the right is a comparison between a modern, low volume mask and it’s older, high volume predecessor.
Materials other than rubber
While rubber remained the material of choice for skirts and straps, early mask manufacturers also created products from plastic, which was a new and novel material at the time. U.S. Divers ran an economically oriented line of masks and fins under the Aquatic brand from 1959 till 1970, calling their form of plastic "Marvil" (TM).
For most though, rubber was the preferred material until the early 1970’s when companies introduced masks featuring a new material called silicone. Its first appearance in the U.S.D. catalog was in 1971 where the Equi-Rama mask was offered with either a rubber or silicone skirt.
Softer, and less prone to cracking, silicone proved itself to be the more popular choice. Rubber masks are still available today but they have become the novelty that silicone once was when it first appeared.
For most though, rubber was the preferred material until the early 1970’s when companies introduced masks featuring a new material called silicone. Its first appearance in the U.S.D. catalog was in 1971 where the Equi-Rama mask was offered with either a rubber or silicone skirt.
Softer, and less prone to cracking, silicone proved itself to be the more popular choice. Rubber masks are still available today but they have become the novelty that silicone once was when it first appeared.
The Modern Mask
If moving from goggles to the single lens design indicates the birth of the basic diving mask; removing the nasal area from within the glass enclosure of that same mask can also be seen as the single most important advancement in modernizing mask design. By doing so, four important obstacles (equalizing the ears easily, purging large amounts of water, widening the field of vision and lowering the internal volume) were overcome and further refinement of the modern mask could begin.
All of these developments, learned by trial and error from the early 1950’s, culminate in the modern diving mask as we know it today.
Low volume and available in either black, clear or coloured silicone; it usually has glass that is custom cut to emphasize downward, but not necessarily horizontal, vision. There are no purge valves and most divers learn to equalize and clear their masks easily within the first few pool sessions.
No longer do divers need to descend in diving bells or chambers, use heavy, bulky helmets or make their own goggles and masks from leather and polished tortoise shell, though many might now pay a premium for the experience. And while the average diver may never need or want to do any of those things, they are worth remembering as an important part of our collective diving history.
All of these developments, learned by trial and error from the early 1950’s, culminate in the modern diving mask as we know it today.
Low volume and available in either black, clear or coloured silicone; it usually has glass that is custom cut to emphasize downward, but not necessarily horizontal, vision. There are no purge valves and most divers learn to equalize and clear their masks easily within the first few pool sessions.
No longer do divers need to descend in diving bells or chambers, use heavy, bulky helmets or make their own goggles and masks from leather and polished tortoise shell, though many might now pay a premium for the experience. And while the average diver may never need or want to do any of those things, they are worth remembering as an important part of our collective diving history.
Sources:
The History of Underwater Exploration by Robert Marx
Dover Publications, New York. 1978. Pg: 14.
Beneath Tropic Seas by William Beebe
Halcyon House / Blue Ribbon Books Inc., New York. 1928. Pg:3-6.
To Hidden Depths by Philippe Tailliez
E.P. Dutton & Company Inc., New York. 1954. Pg: 19, 169.
Learning strategies of Early British Columbia Divers (Thesis). by John Cuthill.
The University of British Columbia, 1997. Pg: 106-107.
The Last of the Blue Water Hunters by Carlos Eyles
G.R. Huttner/Lithography, Los Angeles. 1985.
U.S. Divers Catalogs (Various)
Courtesy of vintagedoublehose.com
The History of Underwater Exploration by Robert Marx
Dover Publications, New York. 1978. Pg: 14.
Beneath Tropic Seas by William Beebe
Halcyon House / Blue Ribbon Books Inc., New York. 1928. Pg:3-6.
To Hidden Depths by Philippe Tailliez
E.P. Dutton & Company Inc., New York. 1954. Pg: 19, 169.
Learning strategies of Early British Columbia Divers (Thesis). by John Cuthill.
The University of British Columbia, 1997. Pg: 106-107.
The Last of the Blue Water Hunters by Carlos Eyles
G.R. Huttner/Lithography, Los Angeles. 1985.
U.S. Divers Catalogs (Various)
Courtesy of vintagedoublehose.com