9 Global Positioning System (GPS) apparatus for use in the field of diving for maintaining course and positioning underwater; sound transmitting and reproduction apparatuses for underwater use in the field of scuba diving; intercommunication apparatus for underwater use for divers; hydrometers; marine depth finders; measurers, namely, pressure measuring apparatus for divers; pressure indicators for divers; temperature indicators for divers; computer interface programs for use in connection with measuring apparatuses, namely, pressure measuring apparatus for divers; decompression chambers; marine compasses; computers, laptop computers, tablet computers, notebook computers for use in the field of scuba diving; computer hardware, namely, monitors for use in the field of scuba diving; computer programs for monitors for use in the field of scuba diving; sound recording equipment for underwater use in the field of scuba diving; transmitters, namely, telecommunication transmitters of electronic signals for use for use in the field of scuba diving; protective films adapted for computer screens for use in the field of scuba diving; nautical apparatus and instruments in the field of diving for maintaining course and positioning underwater, recording, receiving and transmitting audio and video, intercommunication, and pressure, depth and temperature measuring; audio- and video-receivers for use in the field of scuba diving; downloadable computer software applications in the field of diving, namely, downloadable computer software applications for maintaining course and positioning underwater, recording, receiving and transmitting data such as audio and video data, intercommunication, and measuring underwater parameters such as pressure, depth and temperature; processors for central processing units (CPUs) for use in the field of scuba diving; control panels, namely, electrical control panels for use in the field of scuba diving; radar apparatus; masts for wireless aerials; radios for divers; video recorders for use in the field of scuba diving; underwater photo cameras and video recorders