Here is a short account by a former British Army officer who learned to dowse for water in the Sinai desert during the first World war:
“Initiation into dowsing” by J.S. Millar.
What was interesting to me was that the episode the author described followed the Gallipoli campaign, which was a time when the army desperately needed water and dowsing came to the fore, (as mentioned in earlier posts). This obviously left quiet an impression on many officers, since some went on to found the British Society of Dowsers.
The author was taught to dowse by his father, a Lieutenant-Colonel of the King’s Own Scottish Borderers, who it one must suppose used dowsing in his former life as a Water Engineer. But one thing that stands out is that the Colonel was actually map dowsing, to locate promising areas, prior to searching for water on the ground. This makes it the earliest reference to map dowsing that I have so far come across, around 1917 for this account, I would say.