When swimming or diving in waters where sharks may be present, having the right gear and taking the proper precautions is essential for staying safe. One question that often comes up is what color clothing or wetsuit is best to wear to avoid attracting sharks. While there is some debate around this topic, scientific research and expert opinions provide helpful guidance.
Do Sharks See Color?
To understand how color may influence shark behavior, it’s important to first consider what we know about shark vision. Sharks detect color through rod cells in their retinas, but not as vividly as humans do. They have a single cone cell type, making their vision similar to red-green color blindness in humans. So while sharks can see some color, they do not see a full spectrum.
Their vision is adapted much more for detecting contrast and movement. Sharks have a reflective layer behind their retina that allows light to pass through the retina twice, enhancing their ability to see contrast and small details, especially in low light conditions. So when it comes to spotting potential prey, sharks rely more on contrast and motion than color.
How Sharks Perceive Color Underwater
Not only is shark color vision limited, but the properties of light change underwater. The longest wavelengths of light (reds and oranges) are absorbed quickly, while shorter wavelengths (blues and greens) penetrate deeper. This means that any reds, oranges or yellows will appear dark grey or black when submerged.
UV light also travels farther than other wavelengths, and since many sharks are sensitive to UV wavelengths, they may rely on UV cues that are imperceptible to humans.
So from a shark’s point of view, bright or strongly contrasting colors will stand out much more than subtle or muted hues. Background, depth, water conditions, and time of day also affect how visible colors appear underwater.
Research on Shark Vision and Color Perception
While more research is still needed, some key studies provide insight on how sharks respond to color:
– Black and white: A study on bull sharks showed that when given a choice between black and white targets, they preferred to investigate the black target, likely because it stood out better against the lighter water background.
– Red and yellow: Red and yellow are thought to appear grey or black to sharks. One study tested how Caribbean reef sharks responded to yellow, red, and black wetsuits. The sharks did not show a strong preference for any color, suggesting they could not differentiate between them.
– Blue and green: Blue and green are common wetsuit colors. One study tested white, blue, yellow, and black dive fins on Caribbean reef sharks. The blue fins elicited the strongest shark investigative behaviors, suggesting sharks are more attracted to blue. However, another study did not find greater interest in blue over other colors.
– Stripes and patterns: Research on reef sharks indicates horizontal stripe patterns attract more interest and attention from sharks. High-contrast stripes and complex patterns may mimic the natural markings of fish.
So while the evidence is mixed, blues and bright colors tend to attract more shark interest, while blacks, dark greens and non-contrasting solid colors appear to elicit the least interest.
Expert Opinions on Shark-Repelling Colors
Along with research, insights from dive experts and shark researchers can further inform what colors are thought to be safest around sharks:
– Dark neutrals: Many divers recommend darker wetsuit colors like black, grey, and dark blue or green, avoiding bright colors. Black neoprene hides your silhouette and contrast against the environment.
– Avoid yellows: Yellow seems to attract more sharks, possibly because sharks see yellows as similar to whites which stand out underwater.
– No reds: Reds appear black underwater, so while not necessarily provocative, they lose any potentially repelling advantages of bright colors.
– Avoid bathing suit colors: Bathing suit colors like orange, aqua, purple and neon mimic the hues of tropical fish, and may attract curious sharks.
– No skin contrasts: Stay away from strong skin contrasts like wearing dark wetsuits with bare hands or feet. Keeping skin covered reduces defining body contours.
– Camouflage: Matching blue or grey wetsuits and gear to the water color and environment helps divers blend in. AvoidEquipment with shiny metal also reflects light and stands out.
Other Precautions Beyond Color
While color is one factor, other precautions can reduce shark encounters:
– Avoid wearing jewelry, watches, reflective items, or anything that glints.
– Don’t swim alone, especially at dusk or nighttime. Stay close together in a group.
– Avoid areas with known shark feeding or bait fishing activity.
– Steer clear of areas with sewage runoff or fishing scraps that can attract sharks.
– Follow all warning signs or advisories about shark sightings.
– Avoid erratic movements or splashing that can arouse curiosity. Stay calm and swim smoothly.
– Use noise makers, shark deterrent devices, or other proven shark-repelling tools.
– Know how to act if a shark approaches – don’t provoke or flee an initial investigatory pass.
The Best Colors Around Sharks
Based on the evidence, dark or neutral solid colors, especially blacks, darker blues, and greys, are likely the best choices for reducing shark interest. Bright colors, along with high contrast stripes or busy patterns, tend to attract more cautious investigatory approaches.
While color is just one factor influencing shark behavior, keeping gear and wetsuits neutrally-colored is a good precaution to take when in shark-prone waters. Paying attention to other cues, maintaining vigilance, and following safety precautions can also help reduce the risks.
Conclusion
Shark color perception is limited, and the underwater environment distorts how colors appear. Research and expert input indicates dark neutrals like black, grey, and dark blue or green are less likely to attract sharks, while bright colors like yellow and some blues may elicit curiosity. However, many other factors influence shark behavior, so appropriate precautions, vigilance, and an understanding of cues that stimulate sharks are critical for staying safe. Avoiding risky areas and times of day, paying attention to shark sighting warnings, and knowing how to respond in an encounter are also key. While a neutral-colored wetsuit is advisable, it is only one aspect of staying safe in waters where shark hazards exist.
| Color(s) Tested | Shark Response | Study Findings |
|---|---|---|
| Black vs. white | Preferred black | Black targets elicited more approaches from bull sharks |
| Yellow, red, black | No strong preference | Caribbean reef sharks showed similar interest in all colors tested |
| White, blue, yellow, black | Most interested in blue | Blue dive fins elicited strongest investigatory behavior in reef sharks |
| Striped vs. solid patterns | More interested in stripes | High contrast stripe patterns attracted more approaches by reef sharks |
