[EdHornby]

apologies for the gross nature of the post...

do you spit then wrinse, or wrinse then spit? I've found that wrinsing first (and a good long dip, not just a splash) means that the mask gets cold, so there isn't a temperature difference between it and the water, and a layer of spit will stop it from getting condensation building up

However if you dive in cold water there will be fogging to a certain extent, it just means a mid-dive wrinse then fresh spit.

hope this helps....