How Cubism Protected Warships in World War I (opens in new tab)

Wish those were actual photographs and not an artists interpretation for an encyclopedia.

I must admit however it took me a moment to find the bow on this image:

https://commons.wikimedia.org/wiki/File:USS_West_Mahomet_(ID...

I'd wager that it worked very well in many circumstances.

A submarine attack run is extraordinarily mentally demanding for the captain. Every second the periscope is raised increases your chance of being detected, because the wake from the periscope reveals your position and heading. WWI and WWII submarine captains would have been performing complex mental arithmetic to plot the range and heading of surface ships, based on the briefest possible glimpses through the periscope. Sonar was used in both conflicts, but it gave only vague information that needed to be confirmed visually.

Dazzle camouflage would have been worth using if it caused only a hint of confusion. The image through a periscope is already difficult to interpret due to the movement of both vessels and the effects of waves and sea spray; dazzle camouflage added another layer of visual confusion. Forcing a submarine captain to raise the periscope again to double-check a heading or creating a small error in his estimations could have been the difference between life and death.

If you're interested, I can highly recommend this documentary by the BBC on the Royal Navy's Submarine Command Course. It gives a vivid impression of the immense stress experienced by the captain, even during a benign training mission.

https://www.youtube.com/watch?v=H1wr8J-edbo

Yes the impact was likely hit or miss without standardization. Here's a modern-day application : https://en.wikipedia.org/wiki/MARPAT

According to https://en.wikipedia.org/wiki/John_Graham_Kerr, it was mostly Norman Wilkinson's personal success in promoting his ideas that caused the concept to be pursued. (John Graham Kerr, the subject of that Wiki page, had made some progress in convincing Churchill to try a different dazzle scheme a few years previously. It lost favour when Churchill left that post.)

Dazzle paint is still used today by car companies testing new models. The paint schemes arguably hide the curves of the car with dazzle paint. ruining the perception of depth to hide the curves

Dazzle isn't about making it hide, it's about making it hard for a submarine's periscope (before the advent of radar) have trouble figuring out the speed and direction the ship is traveling. Remember, you have to fire a torpedo at where the target is going to be, not where it is.

This is why Dazzle often uses fake bow wakes (an indication of speed) and lines going off in different directions (making it hard to tell the true direction optically).

https://en.wikipedia.org/wiki/Dazzle_camouflage

Important to note that this example is supposed to be artistic, not actually effective as dazzle/concealment. It is a creative design, not a functional one.

https://www.1418now.org.uk/dazzle/