GPS and GOOGLE MAPS TIPS

GOOGLE MAPS AND YOUR GPS

Swimmingholes.info has the lat/lon posted for every individual swimming hole in its listings with a link to a mapping system (mostly google maps) for display.   You can key the lat/lon for a place manually into your GPS or there is now a way to automatically load one in from google maps:  

For how to load a point into a Garmin NUVI or Tom-Tom driving navigator, see GOOGLE MAPS to GPS INFO
(BE CAREFUL - only for places very near a road will these driving navigators produce useful road directions - use our directions when in doubt!)

For how to load a point into a GPX format for a hiking navigator, see GOOGLE MAPS to GPX INFO

For loading more than one point at a time, see below.


ABOUT OUR GPS DATA FILE FORMATS

Swimmingholes.info shows the lat/lon for every individual swimming hole in its listings.  It is gradually being improved to offer complete downloadable GPS data FILES (for DRIVING and HIKING GPS's ) for each state.  

For the HIKING GPS files we use the GPX format (NAD27).  For the DRIVING GPS files we use the GARMIN POI format (NAD83/WGS84).  (See below for a discussion of all this.)  See OREGON for examples of GPX and POI file downloads.  These files are not yet available for all states.


EXPLANATION OF SWIMMINGHOLES.INFO GPS FIELDS:

LATITUDE, LONGITUDE: (this order is REVERSED for DRIVING POI format)

DESCRIPTION:  FOR EXAMPLE: "OR-SWEET HOME AREA-CALAPOOIA RIVERgeneral/nohike"
means:

"OR"=STATE
"SWEET HOME AREA" = Primary name used in web site listing
"CALAPOOIA RIVER" = (if present) Secondary name used in web site listing (corresponds to SUB AREA in web site listing)

"general" = our estimate of the ACCURACY of the coordinates.
DO NOT USE "GENERAL" COORDINATES FOR DRIVING OR HIKING NAVIGATION!
Accuracy codes are as below:
exact:  Means we think that if you get in the swimming hole with your GPS set on NAD83 you will read these coordinates (hopefully). 
approx: Means that we think the swimming hole is within .25 miles of these coordinates. 
general: Means that we think the swimming hole is within .5 to 1 mile of these coordinates. 

"nohike" = our estimate of how close the swimming hole is to a road.
DO NOT USE "HIKE" OR "NOINFO" COORDINATES FOR DRIVING NAVIGATION! 
Hiking codes as below:
hike = Walk over .25 miles from nearest road
nohike =Walk .25 miles or less from the nearest road
noinfo = We have not extracted this info from the directions yet- see the directions in the listing

DRIVING NAVIGATION TO SWIMMING HOLES NOTE:

NOTE:  OUR COORDINATES ARE FOR THE SWIMMING HOLE ITSELF AND MAY BE FAR FROM A ROAD.

Going to a swimming hole is not exactly like going to a Starbucks - (especially if there is a hike involved, of course) but even if there is not much of a hike there is info you need about where to park - how to walk when you leave the parking area (avoiding private property, for instance) - whether to walk upstream or down when you hit the water - safety
issues - etc. etc.   All this info is in the DIRECTIONS part of the web site listing. 

GPS TYPES AND USAGE - GENERAL INFORMATION

We are not experts on GPS usage but we have learned a few things that we might share with you:

TYPES AND TIPS

There are basically two types of GPS units we are concerned with - those for DRIVING use and those for HIKING use.

The AUTO use ones use a road map, the HIKING use ones usually use a topo map.   The better auto ones will say the street name for each turn (called "text to speech") - others just say "Turn left in 500 feet" - we strongly recommend that you get the text to speech (TTS) feature.

If you get an driving one for going to swimming holes, we suggest that you make sure that you can input 1) individual latitude/longitude points and,  2) a file of many latitude/longitude points (often called "Points of Interest" or POIs).  Also, make sure it includes unpaved roads in National Forests, National Parks, BLM lands, etc..  

If you get a hiking one for going to swimming holes, make sure you can input a file of latitude/longitude points (often called "Waypoints") - the cheaper ones dont have data file inputs, you have to key in each point.  Also, on the hiking ones, make sure you get a high sensitivity receiver - usually this is the SIRF chipset.   Under trees or clouds, this will allow you to still get a signal.

Crossover:  You may wish to use the driving GPS for hiking or vice versa.  In our limited experience, if you walk to an off-road lat/lon with a DRIVING PGS, the road map disappears and you will see an arrow pointing directly at the lat/lon point and maybe a (airline) distance to go.  Some of the HIKING GPS's will give road directions BUT they do not "speak" at all - you must look at the map all the time (not good when you are driving!).  At present, there is only one model that does both driving and hiking (awkward -  as you still must input the points twice - in the 2 different formats!) and it is the MAGELLAN CROSSOVER.    We expect that GARMIN will come out with a combined unit in the near future (written 1/2008).

STANDARDS AND FORMATS

There are two poular North American Datum (NAD) standards you will see in these units and it DOES make a difference which one is being used.   NAD27 is the older one used by the USGS topo maps for many years and is the one we use in the swimming hole  listings.  NAD83 is a newer standard (appreantly more consistent internationally).  Hiking GPS units usually are switchable between these and so you can use either.  Auto GPS units seem to use the NAD83 and are NOT switchable.

There are also several different data formats for the latitude/longitude files you would input to these devices.  The hiking ones tend to use the GPX format and the driving ones seem to use a variety of formats, including the GARMIN, KML (used also by google earth) and others. The basic information in all of these is very simple - just the altitude, longitude and a name/description of each point.

CONVERSIONS AND MAPS

Hopefully, there will emerge more standardized formats in the near future, but in the meantime there are some web resources to help make these conversions.

NADCON - To convert between NAD27 and NAD83.

GPS BABEL - To convert between data formats (.txt, GPX, KML, GARMIN, Magellan, etc)

GPS VISUALIZER - To convert files AND produce maps (google maps, google earth maps, etc)