Setting up and using Explorer Chartbooks Bahamas seamless tiled charts in iNavX

Article IX14138, October 18, 2016

In iNavX 5.0.5, from the World Chart screen, tap Charts, then Account and then enter your email and password (formerly Return to the Charts screen and select My Charts, then tap Explorer Chartbooks Bahamas. Select the Quilted Charts option and answer Yes to the prompt to activate charts. Back on the main screen, pan and zoom to the geographic area of the Bahamas area, continue zooming in to particular islands. Whatever chart tiles download at a given scale are cached for future off-line use.


iNavX 5.0.5 (or higher) instructions

From the world chart (basemap), tap the Charts menu in the upper-left corner.


Tap the Account button (upper-left) and carefully enter your email + password. Tap Login and respond to the Success prompt. 


In the My Charts list, this chart product's title is under the Explorer Chartbooks brand category; tap on the Explorer Chartbooks Bahamas item.

Explorer Chartbooks Bahamas title listed under iNavX My Charts screen


In the brief list shown, tap the option for Quilted Charts.


At first, the chart scale is extremely zoomed out to a regional level. Zoom (two finger spreading gesture) and pan (finger drag) into the Bahamas, progressively zooming further into areas of interest.

Reminder: if your device's present GPS position is well outside the Bahamas, the iNavX app will shift the screen away to your current position — which will be a blank gray grid. To avoid jumping out of the chart coverage area, tap the Setting menu (gear-wheel icon, upper-right corner) and set Pos Icon Loc to None.


For every scale of chart area downloaded and presented, that chart data gets cached to memory. The next time you return to the same chart area and scale, iNavX retrieves the chart graphics from memory cache instead of requesting the chart data to download. This means when you are offline, away from Internet access, the charts remain ready for use. 


There are ultimate limits to how far the chart may be zoomed into; finally you reach the last available chart scale.

In some instances, one chart area at a graphically detailed scale lay immediately beside a larger scaled, less detailed chart. That results in somewhat disjointed visuals, here and there, in the chart set — and this is normal, there is no defect; the differences in graphics per scale are an artifact of the finite number of distinct single raster charts that were quilted together to make this final seamless chart set.


Legacy instructions for iNavX 4.7.x


This article happens to show illustrations taken from an iPhone but the instructions are identical iPad usage.

Assuming you have already purchased the Explorer Chartbooks Bahamas product from X-Traverse, now all the downloading is done from inside iNavX. The version of iNavX must be at least 4.7.1 but version 5.0.5 is distinctly better for best use of the charts. You may update iNavX in the iOS App Store utility.

1. On the main screen of iNavX, tap the Add More Charts to menu option. (New to iNavX and can't find that menu? See: Getting back to the main screen of iNavX)

2. Scroll down the long list of different chart and editions, tap on Explorer Charts.

3. When prompted to automatically retrieve available charts (i.e. subscriptions on your X-Traverse account), tap Yes.

Scroll down list of chart vendors and select Explorer Charts

4. The app should return to the main screen but tap the Done button if necessary. On the main screen, tap on Explorer All Bahamas.

On main screen tap on Explorer Bahamas

5. Tap on the Tiled Chart entry (should be listed second from the top).

Tiled Chart selection

6. If you do not immediately see Bahamas charts, probably you are in a distant location and have iNavX set to center on a GPS coordinate outside the coverage area of the collection. You would see the triangular boat icon and a gray empty grid.

Gray grid when far away from Bahamas

If you see the gray grid, tap the Settings icon in the upper-right corner. Set the Pos. Icon Loc. parameter to None. Then tap Save.

Note: Obviously, when you are out on the water actively navigating you will wish to set Pos. Icon Loc. back to Ctr (center). That makes the boat icon reappear and auto-scroll the charts as the boat moves along.

Pos Icon Loc set to None

7. Pan and zoom (i.e. finger drag, two-finger spread) to an area of the Explorer charts of the Bahamas that interests you.

Zooming and panning to Bahamas coverage rectangle

The next few illustrations show a progression of panning and zooming into the Nassau area. The exact graphics you see and the extent of re-scaling available depends on the geographic locale and available survey work at a given scale.

Zoomed out at 132 scaling factor

Zooming in further... notice the scale bar in the bottom left corner...

Zoomed into 13 factor scale

As you zoom in, any smaller scaled chart available with more details will be downloaded on the fly.

Zoomed to 1 point 5 scale

Some text fonts will get increasingly larger; that's expected given the raster charts being tiled. It is possible, here and there, that one part of the screen shows available chart data with a sharp detailed view but immediately next to it there may be higher magnification of a different broader scale chart.

Zoomed to zero point two two

Whatever chart areas you download at a given scale are saved to the memory of your iOS device. That way, when you access iNavX while outside of Internet access range, the cached Explorer Bahamas chart data displays as expected. Before you go out on a wide ranging journey, take some time to download all the chart areas and scales you anticipate needing. There is no "download all" option, all chart content is "on-demand", downloaded as you request it via the action of panning and zooming.

Related knowledge base article:

Quilted tiles of raster charts of different scales may show discontinuities and mismatches of curves, font sizes, contours, resolution - any seamless chart for any software