ARE FULL-FACE SNORKEL MASKS SAFE???

[DiveProKoko]

Are they safe? In a word, no. They're garbage. And yes, I have demoed them....

 

[DiveProKoko]

Versus.....

I know what I'd prefer...

 

[DandyDon]

I used to love snorkeling and free diving before drain valves on snorkels. I did not know about Shallow Water Blackout, but I was lucky.

 

[Wibble]

There are many full face snorkel mask patents, some covering the ornamental or external appearance and others the technical features and internal structural variations, but I eventually found ones that related to an electric fan built into the device for assisting with the airflow. These Chinese patents belong to the Dong Guan City Blue Dolphin Sporting Goods Company Limited and the inventor is cited as Lixiang Liao.

There are two Chinese patents CN201910044057.4 dated January 27 2019 and CN201910484297.6 dated June 5 2019 and these have been followed by US patents US20200231260 A1 dated October 30 2019 and US11097818 B2 also dated October 30 2019. Note that these dates are the filing dates which establish the invention priority, not the patent publication dates which are somewhat later. Patents are also taken out in other jurisdictions to protect the intellectual property in those countries.

Note that issuing of patents does not mean that they are being granted a tick of approval, they just register a claim to the idea as to who came up with it first.

Here is the schematic for one embodiment annotated after reading through the patent text. This version pipes both inlet and outlet air via the snorkel tube, other designs can push exhaust air out via the front of the mask, but the current mask seems to be as the one shown here with an inlet and outlet at the top of the snorkel. The electric fan works on the exhaust side, but any depression created inside the mask is claimed to draw air in from the environment. Basically this mask is using electric fan assist to get around the small bore of the air ducts that hamper these devices, a problem created by trying to use a full face mask with an ambient air supply in the first place. Check valves co-ordinate air movement and shuts things off if water penetrates the float chambers in the snorkel top to cut the power and stop water entering the mask, or at least they do on paper and with everything working properly.

View attachment 729576

Are Chinese patents worth anything? I thought they just stole any tech and copied with inferior technology.

 

[Popgun Pete]

A separate mask and snorkel is the best choice and I had one not long after I learned to swim, so a mouthpiece was no big deal for most kids as that is how they were introduced to snorkelling in the shallows in the first place. However some people never got that start and others just want to try the “latest and greatest” and are captivated by the looks. There is nothing new in snorkel-equipped masks, but if you look at these things the designers have in a sense treed themselves. In trying for a compact shallow mask (fore-aft) they have collapsed the usual mask from a deep rubber body with an integral skirt for face sealing and a face plate clamped at the front to a now moulded and contoured plastic face plate, a thin rim or support frame which is in turn backed by a short rubber/silicone sealing skirt. This frame leaves little cross-section or width to hang large bore snorkels on, compared to the rubber models of the past with sometimes twin big bore snorkels on either side. This in turn limits the snorkel bore apertures, even when rectangular in cross-section, going into the mask, but this very slimness is what distinguishes these masks as a class. The ability to make them by injection moulding has allowed the mask body to be easily replaced by a narrow plastic outer frame, but there is not enough real estate there to do the job and still have that wide body transparent look. Any air channels piped within the frame itself as “buried snorkels” are just too narrow, although that is what most do as bar another snorkel tube there is no other option. Air supplied professional full face masks are fed with pressurised air, so these problems of supplying adequate inflows don’t arise when designing the airflow, but on some of these low cost full face snorkel masks the approach appears to be guesswork or copy someone else who may or may not know what they are doing.

As for patents they are not a tick of approval, they are just a registration of an idea which may or may not work. Patents have to be registered in different jurisdictions to provide any worthwhile protection and need to be defended against copyists, so not always worth doing. In China copying appears to be how most their manufacturers got their start, but this may not always be the case as an interest in taking out patents seems to have arisen there in recent years.