I have had simular problem, Will have large amounts of water pour from my nose after snorkling, much more then when diving. It is due to my breathing from mouth and nose at same time. water pools in mask nose cavity and is drawn up into sinus cavities untill the dive ends. after dive I will just lean over and slightly blow out to release water. I have to always be more aware of my breathing and focus on pulling thru regulator. I got a new mask, and the problem is much less. I have had my nose broken, and have a deviated septum which could add to the problem, not sure though. It is kinda anoying when out, and about. The first time I had a real problem was after a long period of snorkling in Jamacia. I came up on the beach, and the amount of water pouring out my nose would make you think I was drowning. well at least I’m not alone with the problem. Hope you solve it. Hope this helps.