Dazzle or Deception? Rethinking WWI Camouflage Effectiveness
During the tumultuous years of World War I, naval warfare demanded innovation and adaptation. One striking example of this was the emergence of “dazzle” camouflage, also known as “razzle dazzle,” adorning warships of the era. This visually arresting technique stood in stark contrast to traditional camouflage methods that aimed to seamlessly blend objects into their surroundings. Instead, dazzle camouflage employed bold, geometric patterns with the explicit goal of disrupting the perception of German U-boat captains. The intent was to create confusion about a ship’s direction and speed, thereby complicating targeting efforts.
The effectiveness of this novel camouflage, however, has been a topic of ongoing debate. Did it genuinely bewilder enemy submarines, or did it merely present a visually chaotic, yet ultimately ineffective, facade? Now, over a century later, researchers at Aston University have revisited the question, seeking to understand the true impact of dazzle camouflage on WWI battleships. Their investigation involved a re-analysis of a 106-year-old study, shedding new light on the factors that may have influenced its perceived success.
The findings of this re-evaluation, published in Sage Journals, suggest that an unintentional phenomenon known as the “horizon effect” played a significantly more prominent role in the observed deception than the dazzle paint itself. This reveals a critical oversight in the original 1919 analysis of the camouflage technique.
The genesis of the original research can be traced back to 1919, when Leo Blodgett, a student of naval architecture and marine engineering at MIT, undertook a study on dazzle camouflage for his thesis. Blodgett’s approach involved meticulously painting dazzle patterns onto a model battleship. He then observed how these patterns impacted an onlooker’s perception of the ship’s direction of travel when viewed through a periscope. Blodgett ultimately concluded that dazzle camouflage did, in fact, achieve its intended objective of distorting perception.
However, more than a century later, researchers Timothy Meese and Samantha Strong raised substantial concerns regarding Blodgett’s methodology. Their primary apprehension stemmed from the possibility that the observed warped perception might not have been solely attributable to the dazzle paint.
"It’s necessary to have a control condition to draw firm conclusions, and Blodgett’s report of his own control was too vague to be useful," explained Strong, a senior lecturer in optometry, in a statement released by the university. In response to these concerns, Meese and Strong designed and executed their own version of the experiment. They utilized photographs from Blodgett’s original thesis, comparing the results obtained from the dazzle camouflage versions with versions where the camouflage had been digitally removed.
"Our experiment worked well. Both types of ships produced the horizon effect, but the dazzle imposed an additional twist," Strong stated. This observation proved to be central to their subsequent analysis.
The "horizon effect" refers to the tendency of viewers to perceive ships as traveling along the horizon, even when they are moving at an angle of up to 25 degrees relative to it. Furthermore, even when the angle exceeds 25 degrees, viewers generally underestimate the true angle.
Meese and Strong reasoned that if dazzle camouflage were solely responsible for the visual deception observed in Blodgett’s study, then viewers should consistently perceive the front of the ship, known as the bow, as “twisting” away from the actual direction of travel. However, their re-analysis revealed inconsistencies. Specifically, they noted that in certain instances, particularly when the model boat was moving away from the viewer, the onlooker perceived the bow as “twisting” towards them. This suggested that another factor, independent of the dazzle camouflage, was influencing the illusion.
Through careful analysis, they identified the horizon effect as the primary culprit, concluding that it played a far more significant role in deceiving viewers than the dazzle camouflage itself.
Interestingly, the researchers were not entirely unfamiliar with the twist and horizon effects. Meese, a professor of vision science, had previously co-authored a study in 2024 that touched upon these phenomena.
"The remarkable finding here is that these same two effects, in similar proportions, are clearly evident in participants [from the 1919 study] familiar with the art of camouflage deception, including a lieutenant in a European navy," Meese explained. "This adds considerable credibility to our earlier conclusions by showing that the horizon effect—which has nothing to do with dazzle—was not overcome by those best placed to know better."
In essence, even experienced individuals who possessed expertise in camouflage were susceptible to the misleading effects of the horizon. The significance of this finding lies in the fact that, during the era of Blodgett’s original study, "the horizon effect was not identified at all," as Meese pointed out. Therefore, the effect was unknowingly "deceiving the deceivers," undermining the conclusions drawn from the initial research on dazzle camouflage. The new research suggests that the perceived effectiveness of dazzle camouflage may have been, at least in part, a consequence of the unrecognized influence of the horizon effect, leading to an overestimation of the camouflage’s true capabilities. The vibrant patterns may have contributed a layer of distortion, but the fundamental visual trickery was rooted in a phenomenon that remained unacknowledged at the time. The study serves as a powerful reminder of the importance of rigorous control conditions and comprehensive consideration of potential confounding factors in scientific investigations.
