I currently have two map reading “potis”in my rally navigator’s toolbox. As I mentioned in a recent post, I will be competing in the 2017 LeJog rally in the United Kingdom in December. For this rally I plan on using my Don Barrow “poti”. A “poti”, as it is known in rally circles, is a lighted, magnified map reader that not only magnifies the map image, it can be used to measure distances on the map. My “poti” is shown below.
My Don Barrow “Poti” Map Reader
My Don Barrow “poti” has a rheostat switch that allows me to choose between two different white light types. Both lighting types are fine and I’m glad to have two bulbs in case I should have a failure of one of them while in the middle of a rally.
The Map Reader Is About 4-1/2 Inches In Diameter
When I acquired my “poti” from Don Barrow, I could not make up my mind if I wanted a left-hand version or a right-hand version, so I got mine fitted with both handles.
I currently have a 1:50,000 baseplate fitted in my “poti”. This is shown below. The numbers to the left of “0” show the distance in kilometres. The numbers shown to the right are distances in miles. The vertical distance below “0” is useful for checking map plotting coordinates and for measuring “no go” zones or areas that are defined by a radius given in metres. The base plate can be easily changed if another base plate is more appropriate for a given car rally.
I Have a 1:50,000 Base Plate Fitted In The “Poti”
The reason for getting the 1:50,000 scale base plate is that the Lejog (as well as other rallies in the United Kingdom) uses the Landranger Map series which have a scale of 1:50,000 to define the rally route. Coordinates defining the rally route are provided to the navigators, sometimes just before heading out onto the course, who must then plot the coordinates of these key points on the map, determine the route between the key points, then convey this information to the driver. Being able to measure distances on the map is very useful in course following. An example of an unmarked portion of a Landranger Map is shown below.
Each Of The Blue Squares Are 1 Kilometre Square
In the image below, I placed the “poti” over the same portion of the Landranger Map shown above. You can see how easy it is to measure distances using the scale on the “poti” base plate. Depending upon the orientation of the road that you are trying to measure, the “poti” can be easily rotated as necessary.
In Map Rallies, The “Poti” Is A Useful Tool For The Navigator
My other “poti” is also very useful as it also allows me to make marks on the map and to use any map scale that is needed. I have found it to be very useful in the Winter Challenge in Vermont in the USA.
If you have any questions or comments on this post, the “poti”, LeJog, the Landranger Maps, or anything else that I mentioned in this post, then leave a comment below or you can send me a private email message at the following address: shanna12 at comcast dot net