You can look at the route in detail on Bing Maps (see below if that doesn't work properly) by opening this link. This is the recce version of the route over public rights of way. This viewer probably won't work on a smartphone.
Zoom in to see more detail. It goes down to a 1:25000 map. If it's not giving you an Ordnance Survey map, select Ordnance Survey on the tab at the top left of the map (old Bing Maps) or top right (new Bing Maps)
The numbers are of the checkpoints with HQ numbered 15. Numbers 16 and 17 are the two drinks stops. On the new Bing Maps, the display gives the checkpoint names.
You can switch to aerial photo view. If the map locks up, close the page and start again.
If you have previously opted to use the new Bing Maps, you will see the route but the display of the route can be a bit a bit flaky. In the bottom right hand corner of the screen you'll find a semi-transparent menu. Click the Exit button and then Exit Preview on the pop-up window to get back to the old version of Bing Maps where the display is a lot more stable.
Dorset Explorer gives an even more detailed map if you select Base Maps to be Ordnance Survey on the second tab down (below the question mark) on the right hand side, but you'll not have a route marked on it.