I have an Oceanmaster and love it. Was certified with it and learned to clear it the "non-purge" i.e. old fashioned way. If you have a fully flooded mask it is much easier to clear it without using the valve. If you have less than half of it flooded then the purge is handy.
Those with purge masks should always keep the traditional skills up for this reason.
Scubamax
Those with purge masks should always keep the traditional skills up for this reason.
Scubamax