Meanwhile, at sea during the same war, German U-boats were wrecking most of the Allied merchant fleet. The British noticed that the subs stayed far away from any ships that could actually shoot back, so it made sense to disguise the warships as small merchant ships. They also noticed that the subs surfaced when they attacked, so the idea was that they could lure the Germans to what looked like an easy target, then blow them to smithereens when they broke the surface. This was not by itself a particularly crazy idea.
But this disguise had to be convincing, by golly! Historians have written entire books about the British "genius for deception." They had a reputation to uphold, so this is where things got downright weird. The sailors donned costumes, so they wouldn't look like military when viewed through a periscope. Some of them dressed as women and walked around on deck snuggling with other dudes. Some dressed with fake parrots, or in blackface.
"It looks great, man. No way this offends literally everyone in the future."
They even choreographed elaborate displays where once a U-boat was spotted, they would act like panicked civilians and begin to abandon ship while making a show of running into each other and tripping and falling. Some crews would even jump into the lifeboats and pretend to accidentally leave someone behind, and he would stand on the railing screaming for them to come back and get him.