National and international standards and rules for snorkels

[DRW]

The words "snorkelling" and "snorkeller" derive, of course, from the name of the breathing tube enabling the user to inhale air from above the surface when the head is face downwards in the water with the mouth and the nose submerged. Often disdained by scuba divers lacking a thorough grounding in breath-hold diving, the humble snorkel remains key to the act of snorkelling.

I shall dedicate this thread to four Standards (British, German, Austrian and European) and to the World Underwater Federation (CMAS) Surface Finswimming Rules with specifications for snorkels, attempting to determine what they all have in common and what sets each of them apart. In this first message of the thread I shall review British Standard 4532:

The title page above of British Standards Institution (December 1969) BS 4532. Specification for snorkels and face masks. London: British Standards Institution. This British Standard, which was amended on 30 December 1977, is 11 pages in length.

​

Foreword: According to this section preceding the specification proper, "a snorkel allows (the wearer) to breathe without having to raise the mouth out of the water whilst swimming, or floating face downward with nose and mouth submerged." Snorkels used both by the "untrained or casual skin diver" and by the "fully equipped free diver" are covered.

Scope: The Standard specifies requirements for "snorkels (...) used for recreational purposes."

General: This section defines and dimensions the snorkel:

Materials and design: This section elaborates on what is written in the preceding section, specifying the characteristics of the mouthpiece orifice and lugs, the tube, the mask attachment loop and any shut-off valve fitted. Tubes with an internal diameter greater than 20 mm are declared unsuitable for children:

Instructions: The Standard requires a warning label to be affixed to the tubes of all snorkels and a set of instructions to be enclosed with each snorkel. I have posted below the BS4532-prescribed "safety notes" enclosed with a Britmarine snorkel I have in my collection, made by the former underwater gear manufacturer Haffenden-Richborough of Sandwich in Kent in the south-east of England:

Marking: The Standard requires compliant snorkels to be marked with this British Standard's number and the manufacturer's name. Snorkels whose internal dimensions rendered them unsuitable for children had to be marked accordingly:

Appendices: Appendix A describes a "test for rigidity of tube":

So those are the implications of BS4532:1969 for snorkels. I'll finish with a scan of the snorkels page from a 1970s Haffenden-Richborough underwater catalogue referring to BS4532 compliance:

In case the BS4532-related wording on the page isn't clear, here's a blow-up:

Can you work out why the snorkel with the designation B.33 Mariner is non-compliant? It's because it has a soft, flexible, corrugated portion between the mouthpiece and the tube proper, allowing the mouthpiece to hang down vertically and out of the way when the snorkel is not in use. Such an arrangement would cause the snorkel to fail the snorkel rigidity test when applied to the "curve of the tube". Such "concertina" snorkel designs are much rarer nowadays, but there are still one or two around, e.g. the "Seac Corrugated Old Style Snorkel":

However, the snorkel's mouthpiece and collapsible corrugated bend are both made from EPDM rather than natural rubber.

I hope this posting has been of some interest. In my next contribution to this thread I shall be taking a look at the German Standard for snorkels, DIN7878 of February 1980.

 

[Mr. X]

So the standard doesn't like purge valves near the mouthpiece. That seems quite a popular option for snorkellers these days and quite effective for surface snorkeling. My son used a purge valve snorkel for his first few years snorkelling and my wife still does, her's also has a semi-dry top.

I tried a purge valve snorkel for a while; it usually worked well but occasionally the valve stuck open, which could be frustrating. As I mainly spearfish these days, I switched back to a plain J snorkel. But I notice a few spearos use purge snorkels (such as the Riffe model) and/or dry or semi-dry tops, although sometimes just for choppy conditions. Oz-Brit YouTuber Dan Man for a example.

 

[DRW]

So the standard doesn't like purge valves near the mouthpiece. That seems quite a popular option for snorkellers these days and quite effective for surface snorkeling. My son used a purge valve snorkel for his first few years snorkelling and my wife still does, her's also has a semi-dry top.

I tried a purge valve snorkel for a while; it usually worked well but occasionally the valve stuck open, which could be frustrating. As I mainly spearfish these days, I switched back to a plain J snorkel. But I notice a few spearos use purge snorkels (such as the Riffe model) and/or dry or semi-dry tops, although sometimes just for choppy conditions. Oz-Brit YouTuber Dan Man for a example.

British Standard BS4532 is no longer in force and subsequent standards have come up with different priorities in response to changes in snorkel construction. After giving the gist of these later snorkel standards, I'll try to tease out their direction of travel. One thing I can say is that these national and international standards shifted over the years from longer, narrow-bore barrels to shorter, wider-bore ones when it came to achieving the best airflow.

Let's move on to German Standard for snorkels DIN 7878 of February 1980:

2. Deutsche Institut für Normung (February 1980) DIN 7878. Tauch-Zubehör: Schnorchel. Maße. Anforderungen. Prüfung. Berlin/Cologne: Beuth Verlag. Available for purchase from http://www.beuth.de/en/standard/din-7878/2098894

This German Standard, subtitled with the official English translation "Diving accessories for skin divers; snorkel; technical requirements of safety, testing", is no longer in force and just 2 pages in length.

Scope and Purpose: The Standard is designed to cover snorkels intended to enable swimmers and divers to breathe when face down on the surface of the water. The object is to lay down minimum safety requirements to improve diver safety.

Normative references: Another German Standard, DIN 4844 Part 2, relating to safety markings and safety colours.

Concepts: The volume of the device involved in "pendulum breathing" is defined as "Dead Space T."

Dimensions and nomenclature: The Standard provides an illustration to clarify the naming of parts with the proviso that not all snorkels will resemble the image. There is also a table mandating the dimensions for the inner bore of Form A (child) and Form B (adult) snorkels:

For the non-German-speakers, here's a vocabulary list: Schnorchel-Innendurchmesser = snorkel internal diameter; Schnorchellänge = snorkel length; Sicherheitsfarbstreifen = safety colour banding; Haltevorrichtung = keeper; Teleskopeinrichtung = telescopic device; Rohr = tube; Totraum T = dead space T; Kinder = children; Erwachsene = adults; bis = to.

There follows a longish section devoted to safety requirements:
Material: The mouthpiece must be in accordance with German foodstuffs legislation.
Keeper: Snorkel must have a keeper that will not separate from the snorkel.
Mouthpiece: Must be anatomically shaped, all edges rounded to a radius of at least 1 mm.
Dead space: In Form A (child) snorkels a maximum of 120 cm³, in Form B (adult) snorkels, a maximum of 150 cm³.
Safety colour banding: At the supply end of the snorkel there must be safety colour banding at least 30 mm wide in fluorescent orange-red. Safety colour banding made from PVC appears to be long lasting.

Next comes another longish section, dedicated to testing each of the above.
Material: Manufacturer's declaration.
Keeper: A pulling force of 20 N will be used to test the keeper's tensile strength. In the process, the keeper must not detach from the tube.
Mouthpiece: The anatomic design of the mouthpiece will be assessed by visual inspection and by measurement of the radius of the edges.
Dead space: Tested by measurement.
Safety colour banding: Tested by measurement. Colour tested by comparison with the RAL colour standard.

Marking: The Standard required any snorkels complying with its specifications to be marked with the name or symbol of the manufacturer, distributor or importer, alongside the number of the Standard (DIN 7878) and the user category (A or B). Here is a real-life example from the mouthpiece of an Italian-made Salvas Ustica flexible-hose breathing tube identifying the model as an adult snorkel (hence DIN 7878 B):

DIN 7878 of February 1980 was eventually replaced in the Federal Republic of Germany by DIN 7878 of June 1991, whose specifications will be reviewed later in this thread. Next to be considered will be Austrian Standard ÖNORM S 4223 of November 1988 entitled "Tauch-Zubehör; Schnorchel; Abmessungen, sicherheitstechnische Anforderungen, Prüfung, Normkennzeichnung" in German, subtitled "Diving accessories; snorkel; dimensions, safety requirements, testing, marking of conformity" in English and closely resembling German Standard DIN 7878 of February 1980 in specifications.