SurfaceInterval Using a GPS

You can download positional coordinates into a dive site entry from any GPS device which supports the NMEA protocol.

Unlike your Macintosh, a GPS device does not require user input to know its time and location. All that is necessary is to get this information into the Macintosh from the GPS device, and we can then accurately calculate the location of a given dive site.

Follow these steps to obtain positional information from a GPS:

  • If your GPS uses a DB-9 style interface cable, make sure you have a Serial to USB converter connected between that cable and the USB port on your Macintosh. Some GPS units communicate via Bluetooth or USB, in which case no converter is necessary.
  • Make sure you have defined which serial port you will be using in the Serial Port settings panel located in the preferences window.
  • Turn on the GPS and allow it to get a location fix.
  • Make sure the GPS is setup to output its data using the NMEA protocol.
  • Press the GPS button in the Dive Site panel.

After downloading positional information from the GPS, the latitude and longitude fields will be populated by your current geographical position.

An additional benefit to downloading GPS coordinates is that SurfaceInterval can then acurately calculate sunrise and sunset times for dive entries. If Automatic Configuration is enabled in your preferences, SurfaceInterval will toggle the Night Dive checkbox based on these values with respect to the dive start time and duratiion.