What is the best practice when spearfishing/freediving/snorkeling: Retaining the snorkel in the mouth in the diving cycle or remove it before the duck dive and put it back once in the surface?
Personally, I always remove the snorkel. If I am close to my limits, that way I do not have have to purge the snorkel upon surfacing. But am wondering if there is any data on this.
I found this video with spearfishing champions and the majority (if not all) wears the snorkel when surfacing.