OK. I give up
It has happened during the Solomon Islands campaign(if i am not mistaken) in 1943. There were a couple of islands with a strait between them. The American solgiers occupying the islands were afraid of going to the latrines in the jungles, so they have adopted the "japanese" design - two sturdy planks were fixed over water, so one could crap directly into the Pacific without being bit by some tropical bug or a snake.
Unfortunately for the GI's, the same strait has been used by the Arlen Burke's destroyer division to get to the Japanese controlled waters(and get out).
The saiors have noticed by experimenting, that if their vessel's speed was greater than 27 knots, its wake would "flush" over those makeshift toilets, sometimes destroying them. Do not forget - there were the destroyers
.
So, they have started to compete with each other on who "flushes" more of those toilets and paint their "victory signs" on their bridges.
However, their good humor was not appreciated by the Army...
Imagine, you are peacefully squatting and doing your personal things over quet waters and, suddenly, a little tsunami kicks you underwater!
So, the solgiers have been complaining vigorously and Captain Burke had to issue a specific order forbidding this "competition", sign painting and speeds over 25 knots while close to land.
I have read this great story in the famous "History of the US Naval Operations in WWII" by S. E. Morison