Lake Powell App

[thataway]

I was going over my charts for Lake Powell, and came upon the "Lake Powell App" for iPhone or i pad. The basic version is free, the "high resolution" is $9.99. I have the basic version to start with.

https://itunes.apple.com/us/app/lake-po ... 92127?mt=8

What it is an satellite image of the Lake, and you can add features, such as Marinas, floating pump outs, under "services" Under "Canyons" it has a tag on every canyon. It also has "attractions"--such as arches, steps, pictographs. Under "Hikes" it has about 30 hikes, with some info on each hike. It does not substitute for a lake map (I use the Navionics, plus the Garmin Blue Chart on my 10" Chart plotter.

 

[Casey]

Bob, good 'find! It looks very interesting.

Does the $10 version permit a person to enter a lake elevation and thus have a modified shoreline displayed?

Thx!
C&M

 

[thataway]

I dont' have the $10 version, but what I understand is that it shows the shoreline only in high resolution. There are no contours or depths. It would not be a good navigation map, just a supplement to finding features, such as ruins, Oak Canyon Moqui Steps, Pictographs etc. My guess is that the high resolution version will show more precisely where each of these features is. The lake level looks at maybe 3550, but the level at full pool seems to be shaded in over the photo. (Just a guess).

At different pool depths sometimes we say "what canyon is this"--and the app would give the answer, as well as where a trail head is.

There is also an "index", where you click on the feature, and the app takes you to where it is.

I'll download the detailed version when I get wifi.

It is something that if you have an i pad or iPhone, would be fun. I also use the Skipper Top map, and the two Navionics versions (one with one foot contours). The main navigation is the Garmin Blue chart, on the computer.

 

[journey on]

This is a repeat of what I wrote on the Lake Powell Map thread. It discusses using real depth contour maps for the lake.

Here’s what I’ve found out about Lake Powell electronic charting. Works great and can be used on Garmin or Lowrance plotters as well as tablets and phones.

First, remember that the lake level rises and falls during the course of the year. Here’s a link to the present level and a chart showing the difference: lakepowell.water-data.com. As you can see the water level changes by as much as 25’ over the year, so a rock that you can clear at high water, becomes a dangerous obstacle at low water. The Journey On’s Lowrance HDS display comes with a built in chart of Lake Powell (believe it or not), but remember that’s only at one level, which I think is at 3700’.

Next, lakepowellgpsmaps.com sell GPS maps at various lake levels. At each level, the lake level is shown and contours below are in feet of depth. Since all these custom maps depend on the US government (and other govt’s) for their data, I assume the chart is an adaptation of the US Geological Survey, which should make the data accurate. Any way, you can buy a map at the level the lake is when you go there. The lake is full at 3700’ (above sea level,) and the charts go down to 3570’. So, check the lake level and download the map ($50 ea.) There are versions for Windoze, Apple, Android and Garmin. Since I’m using a PC, I downloaded that version.

So, how do you display them? Well the maps (not charts,) are in .MP format, which is a polish format for vector maps. Hooray!!! So at geopainting.com you can download GPSMapEdit. This program displays a huge bunch of formats and certainly does well with .MP.

So, I not only use a PC, but Journey On has a Lowrance HDS Gen 2 MFD. And GPSMapEdit will not only import .MP files, but will export them both for Garmin and Navico (.lgi format) I tried that and it works a treat. Loaded the result on a SD card and tried it. Worked well. So now I have 2 choices.

Finally, how do you try it out to see if you want it? A sample free map of Wahweap is available. The download of GPSMapEdit was free, but I don’t know for how long. Certainly long enough for me to try everything discussed above.

If you have any questions, Frank Marshall (frank@marshall.ms) has been extremely helpful.

Boris

 

[thataway]

How accurate are those maps at the various contour levels?

The lake level changes daily, although at a slow pace.

I have found that all of the maps I have used at Powell, have significant errors, and the most important instrument aboard is the eyeball..