The Modern Navigation Trap

[glenn.225]

Originally Posted by wdkester

You can make copies of the GE cache.

1. Bring up GE and Clear the cache.
2. Traverse the area of interest at the appropriate altitude(s).
3. Exit GE
4. WIN 7 - GE cache is found in C:\Users\{username}\AppData\LocalLow\Google\Google Earth

Copy the following 3 files to a folder
dbCache.dat
dbCache.dat.index
dbroot_cache

5. When you are away from wifi copy these files into the GE folder, bring up GE, and you are set.

Some cautions:
GE changes the file format occasionally, thus destroying your tedious work.

You should set the Cachfile size to the max limit.

You will need to keep an eye on the cache file and save it when it nears the limit. It ovewrites the oldest data.

I have saved the entire ICWW and I think it took 10 or so caches. Unfortunately they have changed the format since; but I got to use it for my last trip down.

Perfect. Thanks, I will be using this. It was on my to do list, looking for a way to do this.

[btrayfors]

Originally Posted by Vasco

Anybody ever use old French charts where the prime meridian ran through Paris rather than Greenwich?

Rick,

Yep, sure have. I had one on the wall of my office in Morocco.

The LAT/LON coordinates were in grads (1/400 of a circle), not degrees!
After conversion to degrees, took me a while to determine why the latitude lines were accurate, but the longitude lines were not....because the zero degree longitude line ran thru Paris, not Greenwich!

Never was able to determine exactly where in Paris....perhaps the home of the chartmaker's favorite whore in Montmartre??

Bill

[conachair]

Originally Posted by valhalla360

Love GE as a backup. The only problem is there isn't a simple way to download an area. In populated areas, you can turn on the internet card in a pinch but for regular use, it eats up a ton of data plan usage and in isolated areas where it's more useful, cell coverage tends to be poor.

There are some after market programs but the ones I've tried are a pain to use.

Ge2kap will do it all for you.

http://www.yachtvalhalla.net/navigat...kap/ge2kap.htm

Also not difficult to have ge2kap follow an Opencpn route and download all the GE images along the way.
Then you have the Google earth images as charts to view in Opencpn.

It's wonderful how generous people write all this code and give it away for free

[valhalla360]

Originally Posted by conachair

Ge2kap will do it all for you.

Creating a KAP chart using OpenCPN and GE2KAP***** Back to Valhalla

Also not difficult to have ge2kap follow an Opencpn route and download all the GE images along the way.
Then you have the Google earth images as charts to view in Opencpn.

It's wonderful how generous people write all this code and give it away for free

I'll have to try this one but I tried a few others and they were far from convienent.

In your example, you show one little bay being captured. Does it work well for say a 40-50 mile stretch? (Example: on the Erie canal the charts are marginal to non-existent, it would be nice to save the whole route.

[conachair]

Originally Posted by valhalla360

I'll have to try this one but I tried a few others and they were far from convienent.

Progs download able from here..

http://www.gdayii.ca/Downloads.php

Depends on your definition of convenient, I found it easy enough. And free

Sent from my SGP312 using Tapatalk

[wdkester]

I was going to mention GE2KAP and GERoute, but thought it might confuse the basic problem of saving caches

GERoute forces GE to travel a route and thus fill the cache. The altitude is dependent on the distance between waypoints; lower when they are closer together and higher when they are farther apart. The heights and distances are setable parameters

GE2KAP will create a KAP file from a GE image by itself, or you can overlay a chart with the GE image. The overlay is most usable when the coastlines are coincident.

[Littlechay]

Originally Posted by Littlechay

What they all said about radar being your friend

trying again to attach the image.

[highseas]

I keep GE images on my laptop of almost every anchorage and harbor from Canada to Mexico.No internet needed to view.Print them out,share with friends.

[Mainebristol]

Originally Posted by Heart of Gold

Mainebristol, an excellent discussion, Thanks for this.

No problem. I'm learning a lot, especially from boatman, so I'm glad I brought it up.

[phiggins]

In your example, you show one little bay being captured. Does it work well for say a 40-50 mile stretch? (Example: on the Erie canal the charts are marginal to non-existent, it would be nice to save the whole route.

Yes GE2KAP will create all the charts along a route. Just create the route using a navigation program like OpenCPN and feed it into GE2KAP's Polygon path field and it will create charts from GE for the whole route. Of course if the route is long and the height low, it could create a lot of charts but it will warn you how many.

The Mexican charts are the reason I wrote GE2KAP after a fellow sailor went aground at Puerto Morelos where the charts are off by a couple of nm.

[Mainebristol]

Originally Posted by Mainebristol

No problem. I'm learning a lot, especially from boatman, so I'm glad I brought it up.

Oops. I meant Dockhead.

[darylat8750]

Wow! What a great thread. Paul the route thing is gold! I'm not much of a teckie but I will learn how to do that.

[Jammer Six]

Originally Posted by Dsanduril

Which argues for crowd sourcing of exactly the information we are discussing. The weather forecasters have (to a certain extent) figured out how to do this and how to weed out bad data and/or correct suspect data.

I'm not sure I buy this.

A cold front being in error by two miles is one thing, Skeeter and Booger reporting a "new" rock in the middle of a shipping channel is another. A few dozen yards one way or the other can matter in the channel, not so much in the weather.

Applying the methods for eliminating "bad" weather data (is there such a thing?) to the location of rocks and shoals sounds like a recipe for a hole in the boat to me.

People are tolerant of inaccurate, inexact, and downright wrong weather data. If you don't believe me, turn on the evening news and listen to what the pros are spewing. Weather "data" is subjective.

The location of a rock, on the other hand, is precise, deadly and unforgiving.

While what Skeeter and Booger think about whether or not it's about to rain might be amusing, delivered in the charming, broken version of English that they both speak, I'm not interested in what either one of them think about the coordinates of Klas Rock.

[ranger58sb]

Originally Posted by captain58sailin

I don't know about the military, but us regular folks don't get DGPS unless we pay a subscription fee. It is supposed to be much more accurate, we use it on Dynamic Positioning vessels when we need to keep a very tight foot print due to operations.

Not exactly. Some GPS units will receive the land-based differential correction signal, hence named DGPS. No extra cost or fee. One of our units is DGPS, and it's actually relatively old.

-Chris

[Canibul]

The differential correction signal is out there. You just need to receive it.