Why isn't there any depth information on my inland G-chart like there is on my offshore G-chart?

Bathymetric information is not readily available for every lake. In addition, because water levels rise and fall frequently, depth information would not be accurate on a consistent basis.

Why doesn't my boat ramp or marina show up?

During production, information on your lake was not available. Please use your GPS to mark the exact coordinates of recreational features, and send us these coordinates as well as a detailed map of the lake. We will review the information and consider including it on our next update. Remember, you also have the ability to create your own waypoint, and designate the appropriate icon, along with your own personal message.

Why doesn't my lake show up?

Garmin® uses the latest available data. If the lake is a fairly new manmade lake or a smaller body of water, it may not be included in our data. Hopefully, the lake will be included when the area is re-mapped. When the data becomes available, we will review it and consider including the lake on the next update.

Are all 50 states complete?

No. The contiguous 48 states are complete, and we have plans to map Hawaii and Alaska in the near future. We also offer one cartridge for the Lake of the Woods.

How much do these cartridges cost?

List price is $99.99 per cartridge.

Why isn't the Intracoastal waterway covered in detail?

The Intracoastal is covered, but not shown in detail on our Inland G-charts. There is detailed coverage of this area on our Offshore G-charts.

Why aren't more roads shown?

Inland G-charts are intended to emphasize inland waterways. We have provided major interstates, with county roads provided around detailed lakes as a secondary reference feature. We are also limited to the amount of data we can provide in one 8Mb cartridge.

Will you have coverage for other countries like Canada or Mexico?

We currently do not have any sources of map data for other countries.

Why is the shape of my lake different than that shown on the G-chart?

Water levels change with rainfall and, as a result, the contour of lakes and rivers change. At the time your lake was mapped, the water level may have been different than the current conditions.

Why aren't rivers covered in more detail?

Because many river systems are such a dynamic feature and change course and channels often, mapping accuracy is questionable. Therefore, obtaining current, up-to-date map data is very challenging.

How accurate are your data sources?

Typically, accuracy is within 160 feet. Also, please take into account selective availability.

Why do more lakes appear at 4nm rather than at 8nm?

Due to limited space of cartridge size, smaller bodies of water appear at 4nm. We also chose to do this to reduce clutter and create a more cosmetically appealing product to consumers.