There are stories floating about that King Ludwig II of Bavaria (1845-1886) electrified a lake to create "waves." Indeed more than one uncited source claims, Ludwig "...electrified a lake to create breaking waves." The location of this electrified lake is unclear.
Some conflate the lake waves with the electric blue lights of the Venus Grotto at Linderhof Palace in Graswang, Germany. A mini palace designed only for Ludwig and servants. The ornate grotto was built in 1878 and glowed with a blue light which was created by an electric lighting system powered by dynamo machines. Light, but no waves. Today it regarded as Bavaria’s first electric power station and the palace and grotto have been restored, but there is no lake nearby and "crashing waves" is inappropriate to the intimate setting of the ornate grotto.
King Ludwig II was known for his eccentricities, budget-crushing castle building, love of Wagnarian opera and a keen interest in technology especially electricity. So it is no surprise that the grotto would reflect both his artistic and technical sides. Indeed he was declared to be "mad" just before his death in a lake, which is still shrouded in suicide/murder speculations.
A more likely locale for the electrified lake, belongs to Lake Starnberg in Upper Bavaria. On its shores stands Berg Castle the annual summer residence of King Ludwig II. He even installed a telegraph at the castle connected to Munich so he could run state affairs from afar. Indeed it is the very lake in which his corpse was discovered, even though he was reputed to be a strong swimmer.
Lake Starnberg makes the most sense for the site of "crashing waves." Ludwig II spent his summers by the lake, understood electricity and could actually enjoy being in water that was warm. Most likely he used electricity to power a contraption of rollers to stimulate waves.
Interestingly, it is on the shore of Lake Stramberg that the first public "Wellenbad" -- literaly "wave bath" was built in 1905. Called the Undosa -- Latin for "the wave kingdom." We can only speculate that that King Ludwig II of Bavaria's electric waves were on the same lake some thirty years earlier, but the existence of the Undosa makes it more likely and makes clear that the waters of the lake were warm enough to enjoy bathing in the summertime.