Mask for surface snorkeling

1. A mask ( 1 ) for surface snorkeling comprising a rigid frame ( 2 ), a transparent visor ( 3 ), a soft face mask ( 4 ) configured to be sealingly applicable to the face of the user and having a membrane ( 7 ) which delimits an upper viewing chamber ( 8 ) being shaped to contain the eyes of the user and a lower breathing chamber ( 9 ) being shaped to contain the nose and mouth of the user, the mask further comprises a first two-way circuit ( 5 ) of forced air exchange induced by a user's breathing, said first two-way circuit ( 5 ) connecting said lower breathing chamber ( 9 ) with the external atmospheric environment, and a second bidirectional circuit ( 10 ) of convective air exchange induced by the temperature difference between the upper viewing chamber ( 8 ) and the external atmospheric environment, said second bidirectional circuit ( 10 ) connecting said upper viewing chamber ( 8 ) with the external atmospheric environment for aeration of the upper viewing chamber ( 8 ) and comprising a diffuser ( 31 ) extending internally into the upper viewing chamber ( 8 ) towards a zone in front of the user's eyes.

2. The mask ( 1 ) for surface snorkeling according to claim 1 , wherein said diffuser ( 31 ) has a tubular shape.

3. The mask ( 1 ) for surface snorkeling according to claim 1 , wherein said diffuser ( 31 ) is delimited by an internal wall of the visor ( 3 ).

4. The mask ( 1 ) for surface snorkeling according to claim 1 , wherein said first two-way circuit ( 5 ) comprises a first connecting conduit ( 11 ) for connecting said lower breathing chamber ( 9 ) to the atmospheric environment external to the mask ( 1 ), and said second bidirectional circuit ( 10 ) comprises a second connecting conduit ( 12 ) for connecting said upper viewing chamber ( 8 ) to the atmospheric environment external to the mask ( 1 ), and in that said first and second connecting conduits ( 11 , 12 ) are equipped with floating shutter means ( 13 a , 13 b ).

5. The mask ( 1 ) for surface snorkeling according to claim 4 , wherein said first connecting conduit ( 11 ) has a passage section which is free throughout its length when said floating shutter means ( 13 a , 13 b ) are in open position thus establishing a direct air connection of said lower breathing chamber ( 9 ) to the atmospheric environment external to the mask.

6. The mask ( 1 ) for surface snorkeling according to claim 4 , wherein said second connecting conduit ( 12 ) has a passage section which is free throughout its length when said floating shutter means ( 13 a , 13 b ) are in open position thus establishing a direct air connection of said upper viewing chamber ( 8 ) to the atmospheric environment external to the mask ( 1 ).

7. The mask ( 1 ) for surface snorkeling according to claim 4 , wherein said diffuser ( 31 ) is arranged on an extension of the second connecting conduit ( 12 ).

8. The mask ( 1 ) for surface snorkeling according to claim 4 , wherein said second connecting conduit ( 12 ) comprises a proximal part ( 12 a ) which opens in said upper viewing chamber ( 8 ) and a distal part ( 12 b ) from said upper viewing chamber ( 8 ), wherein said proximal part ( 12 a ) is connected to said visor ( 3 ) and is made in one-piece with said visor ( 3 ) and said distal part ( 12 b ) is removably engaged with said proximal part ( 12 a ) and supports said floating shutter means ( 13 ).

9. The mask ( 1 ) for surface snorkeling according to claim 8 , wherein said diffuser ( 31 ) has a mechanical or friction or shape coupling with said proximal part ( 12 a ) of the second connecting conduit ( 12 ).

10. The mask ( 1 ) for surface snorkeling according to claim 4 , wherein said first connecting conduit ( 11 ) comprises a proximal part ( 11 a ) which opens in said lower breathing chamber ( 9 ) and a distal part ( 11 b ) from said lower breathing chamber ( 9 ), wherein said proximal part ( 11 a ) is delimited by opposite grooves ( 16 , 17 ) respectively of said visor ( 3 ) and said soft face mask ( 4 ), and said distal part ( 11 b ) is removably engaged with said proximal part ( 11 a ) and supports said floating shutter means ( 13 a , 13 b ).

11. The mask ( 1 ) for surface snorkeling according to claim 10 , wherein said visor ( 3 ) has a front wall ( 18 ) having a flat portion ( 18 a ) which delimits said upper viewing chamber ( 8 ) and an inwardly concave portion ( 18 b ) which delimits said lower breathing chamber ( 9 ), and a lateral wall ( 19 ) which extends peripherally and at the rear of said front wall ( 18 ), wherein said groove ( 17 ) in said visor ( 3 ) is delimited by a partition ( 20 ) that extends from said flat portion ( 18 a ).

12. The mask ( 1 ) for surface snorkeling according to claim 10 , wherein said visor ( 3 ) has a front wall ( 18 ) having a flat portion ( 18 a ) which delimits said upper viewing chamber ( 8 ) and an inwardly concave portion ( 18 b ) which delimits said lower breathing chamber ( 9 ), and a lateral wall ( 19 ) which extends peripherally and at the rear of said front wall ( 18 ), wherein said soft face mask ( 4 ) has a peripheral lip ( 26 ) and wherein the external peripheral edge of said lateral wall ( 19 ) a groove ( 25 ) is formed to house said peripheral lip ( 26 ).

13. The mask ( 1 ) for surface snorkeling according to claim 12 , wherein said peripheral lip ( 26 ) has a peripheral groove ( 28 ) to house said rigid frame ( 2 ).

14. The mask ( 1 ) for surface snorkeling according to claim 4 , wherein said first connecting conduit and said second connecting conduit ( 11 , 12 ) are juxtaposed.

15. The mask ( 1 ) for surface snorkeling according to claim 4 , wherein said first and second connecting conduits ( 11 , 12 ) are positioned laterally with respect to a central axis of symmetry of said visor ( 3 ).