Full-face Snorkel Masks ... Specifications

Dear Undercurrent,

Regarding the letter about full-face snorkeling masks by David Concannon in the November issue:

The British performance requirements for full-face snorkel masks have just been published and set the acceptable limits for work of breathing, and, importantly, inspired CO2 levels. It's now available for all FFSM manufacturers to use, wherever they're based, to compare their product and hopefully improve it to reduce the inspired CO2 levels. It was developed by the same experts who instigated the standards for regulators and rebreathers.

Some people glaze over when "standards" are mentioned, but they're simply reference documents advising manufacturers what they should be testing for and how they should test, and importantly, when you see the standard # on a product, it would be reasonable to assume that it's been tested against industry-recognized criteria.

Measuring the volume weighted average inspired CO2 level in each breath isn't an easy undertaking; it does require the specialist ANSTI test equipment that Mares has invested in. AP Diving (manufacturer of the Inspiration Rebreather) had the first ANSTI system to do that.

Please bear in mind, even if you use a full-face snorkel mask that claims low CO2, ensure the oronasal cup seals properly on your face.

-- Martin Parker, AP Diving

(Note: Undercurrent edited Martin Parker's letter for brevity.)