Towards a typology of snorkels

[DRW]

This morning I decided to conduct a Google search with "snorkel types" as my search term. Among the results, five broad categories emerged for breathing tubes:

1. Traditional/Classic
2. Flexible
3. Dry
4. Semi-dry
5. Full-face

Let us look at each of these snorkel types in turn.

1. Traditional/Classic
The snorkel below is described in several online "snorkel guides" as an example of a "traditional" or "classic" snorkel. One or two even call it a "J-shaped" snorkel, when "C-shaped" seems a more appropriate description:

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So what about the following equally "classic" or "traditional" snorkels below, which may still be in production? They perfectly exemplify the "flexible-hose" snorkel, the "L-shaped" snorkel, the "contour" snorkel and the "J-shaped" snorkel from the illustration below in an early PADI manual. Each of these four types evolved to match different needs and priorities.

Perhaps the wide-bore "contour"-type snorkel labelled as "classic" or "traditional" might be better designated as a "wet" snorkel to distinguish it from the dry or semi-dry variety. I'll take a critical look at the other four "types" in subsequent postings and then come up with a better set of types that might even amount to a coherent snorkel typology! Please feel free to contribute your own take on the matter.

 

[DRW]

"Flexibility" may sound like a simple enough concept to apply to snorkels when determining type, but what form does it take in practice? In its most extreme form, nowadays,flexibility covers "collapsible" breathing tubes that can be so reduced in size by folding them up that they can fit inside a pocket out of the way but ready to use, e.g. the following "elastic snorkel":

Then there are snorkels that are partially flexible, such as the flexible-hose snorkel that has been around since the 1950s:

The corrugated hose between the mouthpiece and the barrel drops out of the way when the mouthpiece is not in use. There are many other combinations and permutations of flexibility, such as snorkels with flexible joints allowing the position of the mouthpiece to be adjusted to the user's specifications and maintained in that position. Some J-shaped breathing tubes have a straight hard barrel and with a combined soft-rubber elbow and mouthpiece attached that will pull less on the jaw in use and hence cause less fatigue over prolonged sessions in the water.

All the above may satisfy the criterion of flexibility to a greater or lesser extent. In other words, it may be better to envisage partial or total snorkel flexibility on a spectrum from total pliability to total rigidity. It also makes sense to bear in mind what problem the relative flexibility or otherwise of a snorkel is seeking to solve. Foldable and flex-hose breathing tubes were designed to be particular responses to two completely different requirements and ne'er the twain shall meet!

 

[DRW]

Let us proceed now to dry and semi-dry snorkels. The terms "wet", "dry" and "semi-dry" first applied to diving suits and only recently extended their applicability to breathing tubes.

Dry snorkel

Here is one explanation of its workings: "A dry-top snorkel means that there is a special part on the top of the tube that doesn’t let water into the tube when a wave comes over the snorkelers. It completely seals the tube if it is submerged. Since the snorkel remains dry, you can start breathing immediately after resurfacing without clearing the tube." What users of the term "dry(-top) snorkel" seldom do is mention that certain mid-twentieth-century snorkels claimed to do the same thing:

The image above from Peter Small's excellent little book Your Guide to Underwater Adventure (1956) records a family seaside holiday moment where the girl sitting in the foreground is equipped with a Typhoon T1 anodised aluminium double-bend snorkel topped with a ball-in-the-cage shut-off valve performing exactly the same function as the modern dry snorkel showcased earlier. Six decades ago there were alternatives to the ball-in-the-cage valve such as the float valve, which worked on hinge or sliding basis. The main point is that "dry" snorkels were not suddenly invented after their mouthpieces converted from rubber to silicone, they go all the way back to the 1950s. The only difference between the historical dry snorkel and the modern dry snorkel is the minutiarisation of the valve parts in the latter.

So much for the "dry snorkel" as a snorkel type. The modern "semi-dry" snorkel can be similarly explained: "A semi-dry snorkel has a splash guard on the top of the tube that prevents water entry when a wave comes over, but doesn’t seal the tube. This means, that if you submerge, the tube will fill up with water. This feature makes it a good choice for scuba diving. Most semi-dry snorkels also include a flexible tube for the best fit."

Semi-dry snorkel

Note both the term "splash guard" for the device fitted to the top of the tube and the limited function it performs in excluding water on the surface but letting it in during submersion. This is no modern miracle either. The Typhoon T1 snorkel below from the 1950s also sported a splash guard:

In the case of the 1950s breathing tube, the splash guard took the form of a rubber "cap valve" with a loose-fitting base fastened to the top of the barrel, which had holes drilled into its sides. Fresh air passed from the atmosphere through the loose-fitting base of the cap valve, through the holes in the barrel and down to the mouthpiece. During submersion, of course, water got into the cap valve base and the barrel, but on the surface the arrangement kept the bulk of the water out, even when it was choppy. So "semi-dry snorkels" go all the way back to the 1950s as well.

There appears to be plenty of mileage, therefore, in the "wet", "dry" and "semi-dry" typology for snorkels ancient and modern, but it must also be remembered that the typology is confined to the watertightness or otherwise of a snorkel and tells us nothing about the snorkel's shape, dimensions, orientation (frontal/lateral), materials or any special features it may have such as a drain valve or collapsibility/adjustability/flexibility.

The fifth snorkel type, "full-face" or otherwise, must wait for another time. It introduces a different snorkel typology, whether the breathing tube is a stand-alone or integrated into a diving mask, and if the latter, does the mask cover the mouth as well as the nose and eyes? Watch this space.