A multi-user virtual reality system for providing a virtual reality experience to a plurality of users in a body of water includes a reference system adapted for emitting and/or receiving signals. The multi-user virtual reality system includes equipment configured to be mounted to a first user in the body of water, wherein the equipment includes a first display unit and a first signal emitting or receiving system adapted for emitting and/or receiving signals. The multi-user virtual reality system includes equipment configured to be mounted to a second user in the body of water, wherein the equipment includes a second display unit and a second signal emitting or receiving system adapted for emitting and/or receiving signals. The multi-user virtual reality system includes a data processing system including one or more data processing units. The data processing system is configured for determining a position of the first user in the body of water based on at least one signal transmitted between the first signal emitting or receiving system and the reference system. The data processing system is configured for determining a position of the second user in the body of water based on at least one signal transmitted between the second signal emitting or receiving system and the reference system. The data processing system is configured for determining whether the second user in the body of water is within a first target region 480 relative to the first user in the body of water. The data processing system is configured for instructing the first display unit to display virtual reality content to the first user in the body of water. If it is determined that the second user in the body of water is inside the first target region relative to the first user, the displayed virtual reality content includes a representation of the second user.

A multi-user virtual reality system for providing a virtual reality experience to a plurality of users in a body of water includes a reference system adapted for emitting and/or receiving signals. The multi-user virtual reality system includes equipment configured to be mounted to a first user in the body of water, wherein the equipment includes a first display unit and a first signal emitting or receiving system adapted for emitting and/or receiving signals. The multi-user virtual reality system includes equipment configured to be mounted to a second user in the body of water, wherein the equipment includes a second display unit and a second signal emitting or receiving system adapted for emitting and/or receiving signals. The multi-user virtual reality system includes a data processing system including one or more data processing units. The data processing system is configured for determining a position of the first user in the body of water based on at least one signal transmitted between the first signal emitting or receiving system and the reference system. The data processing system is configured for determining a position of the second user in the body of water based on at least one signal transmitted between the second signal emitting or receiving system and the reference system. The data processing system is configured for determining whether the second user in the body of water is within a first target region 480 relative to the first user in the body of water. The data processing system is configured for instructing the first display unit to display virtual reality content to the first user in the body of water. If it is determined that the second user in the body of water is inside the first target region relative to the first user, the displayed virtual reality content includes a representation of the second user.

A diving mask includes a transparent visor, a frame, a gasket to guarantee the watertight seal and appropriate belts for fitting the mask, a breathing tube associated with the facial part is fitted onto the upper part of the mask and which enables the flow of air to enter into the compartment between the frame and the visor. The path of air in the inhalation phase and in the exhalation phase both in the mask and tube are different from each other. The tube is made with separate ducts for inhalation and exhalation and the inside of the mask is made with two compartments, one upper front and one lower oronasal separated by a wall. The path provides that inhalation air is introduced by the tube into the frontal compartment and then into the oronasal one and air exhaled from the oronasal compartment travels up to the tube.

A diving mask includes a transparent visor, a frame, a gasket to guarantee the watertight seal and appropriate belts for fitting the mask, a breathing tube associated with the facial part is fitted onto the upper part of the mask and which enables the flow of air to enter into the compartment between the frame and the visor. The path of air in the inhalation phase and in the exhalation phase both in the mask and tube are different from each other. The tube is made with separate ducts for inhalation and exhalation and the inside of the mask is made with two compartments, one upper front and one lower oronasal separated by a wall. The path provides that inhalation air is introduced by the tube into the frontal compartment and then into the oronasal one and air exhaled from the oronasal compartment travels up to the tube.

A method and system to deliver to a submerged diver only that amount of breathing gas volume and pressure required at the diver's depth by controlling the actions of a valve in response to inhalation demand. A sensing unit detects diver respiration, and a logic unit controls a valve to deliver breathing gas to the diver from a breathing gas source via a tube.

A method and system to deliver to a submerged diver only that amount of breathing gas volume and pressure required at the diver's depth by controlling the actions of a valve in response to inhalation demand. A sensing unit detects diver respiration, and a logic unit controls a valve to deliver breathing gas to the diver from a breathing gas source via a tube.

A structure of an underwater sports mask includes a lens frame, a lens portion and a water sealing skirt. A central area of the lens frame is provided with a positioning device for connecting a frontal breathing tube, and the positioning device allows the breathing tube to move along the axial direction of the breathing tube.

A structure of an underwater sports mask includes a lens frame, a lens portion and a water sealing skirt. A central area of the lens frame is provided with a positioning device for connecting a frontal breathing tube, and the positioning device allows the breathing tube to move along the axial direction of the breathing tube.

The present invention provides a retaining device for connecting a mask and a snorkel. The mask has a head strap and a positioning ring, and the head strap freely passes through the positioning ring. The retaining device comprises a male fastening element and a female fastening element, which is connected to the male fastening element. The male fastening element is connected to one of the positioning ring and the snorkel, and the female fastening element is connected to the other. The user may assemble or separate the mask and the snorkel with the retaining device of the present invention, and there wouldn't be relative linear displacement between the mask and the snorkel in use due to buoyancy and gravity.

The present invention provides a retaining device for connecting a mask and a snorkel. The mask has a head strap and a positioning ring, and the head strap freely passes through the positioning ring. The retaining device comprises a male fastening element and a female fastening element, which is connected to the male fastening element. The male fastening element is connected to one of the positioning ring and the snorkel, and the female fastening element is connected to the other. The user may assemble or separate the mask and the snorkel with the retaining device of the present invention, and there wouldn't be relative linear displacement between the mask and the snorkel in use due to buoyancy and gravity.