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australia:navigation

navigation management for hikers

Introduction

  • getting lost in the Australian bush is a major risk - everything tends to look the same and usually there is no mobile internet to help you when you most need it
  • it is important to have a map and compass as well as smartphone or GPS, and recovery options such as carrying an EPIRB and to inform others of destination and expected return time prior to departure

Using a compass and map

  • get a good compass and a topographic map for the area you will be hiking in
  • know how to use the compass and map
    • learn how to set a compass bearing to a visualised target so you can keep walking in a straight line to the target even if you lose sight of it
    • learn how to position a map to true north based on the magnetic north of your compass and determine a bearing from the map to get to a desired destination
    • learn how to use two recognisable and visible landscape features to triangulate your position on the map

compasses

  • most compasses are optimised for the hemisphere in which you will be to make it easier to adjust for magnetic north
    • most Silva compasses are balanced for a specific region and are designated MN (north hemisphere), ME (Equatorial) and MS (southern hemisphere)
  • some compasses are global and can be used anywhere in the world
  • compasses can lose magnetism or reverse polarity if stored close to a microwave device (EPIRB, smartphone) or magnetic material such as Apple iPhone MagSafe, etc
  • compasses become inaccurate if used near other compasses, magnets, batteries, metallic objects, etc
  • most compasses with glow in the dark markings are phosphorescent and require initial light then last for some 4 hours, some military grade compasses use radioactive material and do not need to be primed by light and will glow continuously for around 7 years
  • some compasses have an adjustment screw to manage magnetic declination map error, others you need to adjust manually
  • some compasses are marked in 360 degrees and some are marked in the more precise 6400 mils (milliradians) which is what is used in the military for artillery purposes
  • some compasses are “lensatic” which means they use a magnifying glass set at 45deg angle to the compass to more accurately line up a bearing line
    • the base plate compasses utilise the Silva 1-2-3 navigation system
  • lensatic military compasses
    • the tritium versions of thee are generally the best compasses for night time use
    • these are used VERY differently to base plate or mirror compasses
    • Cammenga Lensatic Tritium USGI Compass
      • $AU244
  • compasses with mirror sightings
    • the mirror allows more accurate bearings to be taken (mainly an advantage in open terrain over long distances) but are heavier and more bulky
    • SUUNTO MC-2G
      • global needle; clinometer; luminescent; adjustable declination easily adjusted with the adjustment key which is attached to the lanyard; nice sized viewing notch in the mirror;
      • $AU99-129
      • the new model has a Slope card and a Scale lanyard, and the new graphics contain a more distinct arrow and a more contemporary font
      • map-measuring scales in mm or inches, 1:25,000, 1:50,000 and GPS scales
      • can also map-measure 1:40,000
      • clinometer
      • luminous markings but none on the North needle limiting its utility at night; 86g;
      • $AU119
      • $AU74
  • other high quality compasses
    • Expedition 54B 6400-6400/360 Military Compass
      • Expedition 54 is a unique compass featuring both an optical precision sighting system and a SILVA 1-2-3 SYSTEM compass in the same unit which is great for artillery purposes but probably unnecessary for hikers.
      • B designation = Beta illumination Tritium compound 80 mCi which lasts for 7.5 years (hence discounted models may be at end of life!) and is not light activated, whereas the Expedition 54 has a light activated luminous compound which illuminates up to 4 hours
      • Precision sighting scale: 1 / 20
      • Measuring scales on base plate: 1:25k, 1:50k, 1:40k, mm, inch
      • UTM position plotting scales (Romer scales): 1:25k, 1:50k, 1:40k
      • Accuracy: +/- 0.5 degree (8.9 mils)
      • Settling time from 90 degree angle to complete rest: 6 sec
      • IP68
      • no clinometer or declination adjustment
      • $AU399
    • Expedition 4:
      • Accuracy: ± 1° (17.8 mils)
      • 4hrs illumination
      • UTM position plotting scales (Romer scales): 1:25k, 1:40k, 1:50k
      • Settling time from 90° angle to complete rest: 5 sec
      • 36g
      • $AU99
    • Expedition:
      • luminous markings
      • clinometer
      • can map-measure 1:40,000
      • Scales: 1:25k, 1:40k, 1:50k, GPS scales, Lanyard; 1:25, / 1:50, mm, inch
      • slope card, scale lanyard
      • 50g
      • $AU69

Using a smartphone

  • bring a compass and topographic map as backup as well as an EPIRB especially if you are going out of internet range
  • ensure you download maps for the area BEFORE going there as internet access is probably NOT available
  • turn off WiFi and BlueTooth to conserve battery power
  • ensure you take a USB power pack as your smartphone battery will not last long with GPS running

UHF CB Radios

  • NOT useful for emergency communications due to limited coverage
  • generally not worth carrying while hiking, except for group management purposes
  • they are popular with 4WD convoys and for groups of hunters

Consider taking a satellite communicator

  • much more affordable than a satellite phone, a satellite communicator just sends txt messages - no voice.
  • a satellite communicator requires a satellite service subscription although usually you can just get a 1 month subscription relatively cheaply (eg. $AU54 annual fee plus $AU25 for a month on Iridium freedom plan) and this will allow a certain number of free messages with extra messages and premium weather messages (hourly forecasts instead of 6hrly plus more days) charged.
  • example:
      • this require a subscription to the Iridium Satellite network which lets you send and receive custom and preset text messages or emails with a delivery confirmation.
      • requires clear view of the sky to function
      • can Bluetooth pair with your smartphone via the Earthmate app to provide a user interface for texting, maps, location sharing etc
      • can do two way messaging to other InReach devices
      • can contact GEOS emergency services to activate rescue and get advice via the SOS feature
      • can update a Garmin mapShare webpage to display to friends and family where you are by optionally sending track points at 10 minutely intervals and they can also request a location data to be sent to them.
      • every inReach device comes with free access to a cloud-powered portal to plan your trips with routes and waypoints, create preset messages and quick texts, sync and manage your device settings, update your firmware, download additional TOPO maps, link your social media accounts, store all your location tracking data
      • turn off Bluetooth and Ant+ to save battery, plus keep it turned off if you don't need to do tracking;
      • having tracking on uses more battery but does mean your family and friends can see where you are and if you do fall off a cliff and can't activate the SOS at least they can see where you were!
        • an alternate method is to send them manual preset messages every so often which will save battery power.
        • 20 days use in power saving mode (Extended tracking mode)
        • for most people this will be a better buy than the much larger, heavier Explore model
        • adds preloaded DeLorme® TOPO maps with onscreen GPS routing plus built-in digital compass, barometric altimeter and accelerometer
        • NOT great for navigation using the maps! Need to create navigation routes on website BEFORE hiking and you must put in a series of way points to create straight line routes - no good for winding trails!
        • NOT compatible with other Garmin maps!
        • NB. SE version is slightly cheaper and yellow but does not come with maps or the built-in digital compass, barometric altimeter and accelerometer
    • ZOLEO Global Satellite Communicator
      • no user interface requires Bluetooth to smartphone
      • basic $AU32/mth plan with Iridium
      • creates a dedicated Australian mobile phone number and email address for messaging

Take a personal EPIRB radio beacon

  • this device has ONE JOB only - to send a continuous radio distress signal if you activate it
  • battery lasts around 2 years usually
  • they need to be registered with the local radio beacon service
  • the main downside is they will not activate if you fall off a cliff !
australia/navigation.txt · Last modified: 2021/06/13 01:31 by gary1