HSIWatch App for Android Watches

Always be skeptical regarding any information provided by HSIWatch. Accept it only if and when it is confirmed by navigation methods such as FAA approved chart visual references and FAA approved electronic navigation systems. EXPECT it to FAIL when someone's HeALTh or PROpeRTy is at RISk.

Privacy policy: The only personal information used by HSIWatch is location, which is used only for updating the display and optionally forwarding it to other devices, all at the user's explicit direction.

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Page Map

Waypoint Entry
Nav Mode Select
Nearest Airport
Airport Information
start Nav Dial
Moving Map
... menu pages ...

Nav Dial Page

OBS setting ▶
course to waypoint ▶
course from waypoint ▶
distance to waypoint ▶
time to waypoint ▶
◀ ground track
◀ altitude
◀ ground speed
◀ waypoint ident
◀ navigation mode
  • OBS setting - where the yellow triangle is, indicating selected course or radial.
    • drag finger around number dial to change OBS when in GCT,VOR,ADF modes
    • LOC,LOCBC,ILS modes lock the OBS in place
  • course to/from waypoint - indicates the OBS setting needed to center the needle
  • distance to waypoint - indicates nautical miles to the selected waypoint. italics indicate slant-range distance (when elevation of waypoint is known), normal text indicates over-the-ground distance.
  • time to waypoint - distance / ground speed, ie, time to waypoint if headed directly to waypoint. --:--:-- indicates time in excess of 100 hours.
  • ground track - course line currently following over the ground as measured from GPS, same as red airplane icon. ---° indicates ground speed too low to determine track.
  • altitude - feet MSL as measured from GPS
  • ground speed - indicates ground speed in knots as measured from GPS
  • waypoint ident - waypoint being navigated to
    • case-insensitive, and spaces are ignored
    • accepts airport ICAO id (eg, KBOS or 2B2), VOR or ADF id (eg, BOS), fix id (eg, BOSOX). airport FAA ID accepted (eg, BVY) if not same as VOR.
    • accepts localizer IDs (eg, IBVY or I-BVY).
    • accepts aptid.rwyno (BOS.4R, BOS.04R, KBVY.27, 2B2.10) for runway provided the runway lat/lon data is in the FAA database. the . is optional and the leading 0 for runway numbers is optional, ie, 7B3.02, 7B3.2, 7B302, 7B32 are all the same. when selected, you are presented with a dial of a generic ILS lined up on the runway. this generic ILS may very well indicate a course that is obstructed, therefore it is usable only when the pilot is able to verify that the path is clear.

    To select a waypoint, swipe downward on the nav dial page to open the waypoint entry page.

  • navigation mode - indicates current navigation mode
    Valid for all waypoints:
    • OFF - stops GPS reception
    • GCT - track great-circle course to waypoint
      • start of course is what current position was when waypoint was entered or app was started (whichever was later)
      • end of course is the entered waypoint
      • OBS initially set to great-circle course from starting position to entered waypoint
      • OBS automatically updates as flight progresses along course to track great-circle course
      • needle indicates off-course (crosstrack) distance in degrees similar to VOR
      • to re-center needle, either:
        • manually rotate OBS dial
        • tap on waypoint id which opens keyboard, then tap enter to reset course from current position to the same waypoint
    • VOR - standard HSI/OBS dial nav to/from waypoint. treats all waypoints as if they were a VOR, even localizers.
    • ADF - ADF-style needle points to waypoint. treats all waypoints as if they were an NDB.
    Valid only for localizer waypoints:
    • LOC - standard HSI/OBS dial nav on localizer course line
    • LOCBC - standard HSI/OBS dial nav on localizer back-course line
    Valid only for localizer waypoints with glideslope:
    • ILS - standard HSI/OBS dial nav on localizer course line including glide slope
      • WARNING Altitude is notoriuosly inaccurate in these devices so be doubly cautious when using the glide slope indication provided by this app.

To access the other pages, touch near the center of the screen, and a diagram will appear:

Swipe in the direction of the double arrows to select the function wanted:
  • exit - close the app (must be swiped twice)
  • map - open the moving map page
  • menu - access the menu pages
  • waypt - enter waypoint being navigated to
You must touch in the area of the menu to get the menu to appear. Touching near the edges will rotate the nav dial (if current nav mode allows it).

Menu Pages

  • ◀BACK - goes back to nav dial or moving map page
  • SATS - show GPS satellite status (also has a magnetic compass)
  • GPS - selects GPS source (see below)
  • UPDDB - download database update (requires Internet access)
    • GREEN - database is up to date and will remain so for a few days
    • YELLOW - database is up to date but will expire soon
    • RED - database is expired
  • HSI - select HSI mode for nav dial (airplane always at top); else OBS with yellow triangle always at top
  • Ambient - slow to 20 seconds per GPS sample in ambient mode; else maintain 1 second per sample
  • Simplify - simplify nav dial page allowing text to be enlarged
  • Time Dots - display time received from GPS as dots around the perimeter of displays
    • RED dot indicates HOURS
    • GREEN dot indicates MINUTES
    • BLUE dot indicates SECONDS
  • SEND - send location to another device using bluetooth and/or UDP
  • MORE▶ - goes to next menu page
  • ◀BACK - goes back a page
  • Fill Chin - has nav dial fill chin on devices with a chin (only present on devices with a chin)
    Filled ChinEmpty Chin
  • ABOUT - display version and database expiration information
  • EXIT - close app
  • RESET - reset settings to factory defaults and purge database

Moving Map Page

zoom out
  • GREEN - airports (up to 20 with longest runways)
  • CYAN - VORs (if not 20 airports)
  • YELLOW - range ring at half radius
  • MAGENTA - course line and destination waypoint
    course line shown is always great circle regardless of mode selected for nav dial page
zoom in

The moving map page can be accessed by swiping right-to-left on the nav dial page.

To access the other pages from the moving map page, touch near the center of the screen and a diagram will appear:

Swipe in the direction of the double arrows to select the function wanted:
  • back - go back to nav dial page
  • menu - access the menu pages
  • near - access nearest airport selection page
  • rwys - display runway diagram for current airport

Voice Recognition

Voice can be used to input the waypoint identifier being navigated to on the waypoint input page. It can be selected by clicking the VOICE button on the waypoint input page. It recognizes the usual aviation prowords (alpha, bravo, etc) and the decimal digits (see table below).

NOTE: Some watches may not have voice input capability.

NOTE: This feature may require internet access to function. Usually displays a message indicating unable to connect to Google or something similar. Swipe the voice input panel away then uncheck the Voice checkbox then use keyboard input instead.

  1. open the waypoint input page by swiping downward on the nav dial page
  2. tap the VOICE button, speech entry page should show
  3. tap microphone icon on speech page
  4. say prowords for the desired waypoint
  5. click checkmark icon

List of recognized prowords (other words are ignored):


Selects which GPS device is used.


Transmits GPS positions (either real or simluated) on Bluetooth and/or UDP (WiFi) to such as a tablet or phone based EFB app. Uses NMEA GPGGA,GPRMC messages to send GPS position reports.