Step 1 Get and install qtVlm (version 5.8 onwards) onto the target machine. Free for "Desktop" machines
Step 2 Pay for and download the VMH chartset required onto a "Desktop" machine. It will arrive in a .zip folder. Extract contents. There will be 2 files, a .vmh file and a .hdx file. Save the original shopping cart email CAREFULLY. It has the 2 Unlock codes. It looks similar to this
Step 3 Place the * .vmh file and the matching * .hdx file either (a). Find the qtVlm installation folder and put in the MBtiles folder. OR (b). put them in a folder somewhere handy where you will be able to find it. These are BIG files. For Android installations the best plan is to copy the 2 files to a folder and copy that folder onto an SD card, and plug this into your tablet. For iOS the charts can be transferred via airdrop or iTunes. The crux of the matter is to get the chart folder onto the target device and have it somewhere where you can find it again. NOTE: You can make copies of the charts and save carefully elsewhere.
Step 4 Activate the charts. You need to be online for this bit. Start qtVlm, click the qtVlm header and choose Configuration
In the window that opens, choose the Maps tab, then Folders:
In this case we put the VMH charts folder straight on Disc C and pointed qtVlm at it, then clicked OK:
Now Click VMH activation, highlight the chartset you're activating, click Activate, then type in your 8 digit unlock code and click OK:
Activation acheived and confirmed. Note the 8 digit code you have just used can be used again but ONLY on this machine (in case you accidentally delete the program and have to start again). Make a note of which machine(s) you used each code on.
Get the underling map over an area you have got covered with your charts, the toggle the "M" button
At this stage your charts are locked to the target machine/device and are useable whenever you run qtVlm in future. Updating the program in future should not lose your activation/charts.
Hints and tips
No 1. As you zoom in and out the images can look "grainy". They settle after a couple of seconds.
No 2: Holes in the charts ! These are where you are seeing the underlying mapping coming through in areas where there is no chart (often over land areas, sometimes between adjoining chart tiles) If an area you want has a "hole" in it !!!, Zoom back a bit till the underlying charts "cover" the hole, then LOCK LEVEL by clicking the "M" button. Now that image mix will remain as it is and you can zoom in a bit more without it changing charts. Basically you will be LOCKING the zoom at a single level and preventing automatic chart switching. To go back to auto switching, toggle the M" button again.