The distance you can see in the ocean depends on whether you mean above the surface or underwater, as well as on environmental conditions.

Above the Ocean Surface

• For an average person standing at sea level (eye height about 6 feet), the maximum distance to the horizon is roughly 4.5 kilometers (about 2.8 miles) due to the Earth's curvature

• This distance can increase if you are higher above sea level (on a ship's deck, lighthouse, or cliff), allowing you to see farther. For example, a lighthouse light might be visible from more than 20 kilometers away under ideal conditions

• Weather conditions like fog, haze, and mist can drastically reduce visibility, sometimes to less than 1 kilometer in dense fog

Underwater Visibility

• Visibility underwater is limited primarily by water clarity, turbidity (particles suspended in water), light penetration, and biological factors

• In very clear ocean water, horizontal visibility can extend up to about 80 meters (around 262 feet), which is near the theoretical maximum

• Typical underwater visibility in most ocean waters is often much less, commonly ranging from a few meters to 30 meters depending on local conditions like plankton density and suspended sediments

• The Secchi disk method has recorded a maximum underwater visibility of about 80 meters in the Eastern Weddell Sea, Antarctica, which is exceptional clarity

• Light attenuation underwater means that colors fade and contrast reduces with distance, making objects harder to see beyond certain ranges even in clear water

Summary Table

Environment| Typical Maximum Visibility| Influencing Factors
---|---|---
Above ocean surface| ~4.5 km (2.8 miles) at eye level| Eye height, Earth's curvature, weather
Underwater (clear ocean)| Up to ~80 meters (262 feet)| Water turbidity, light penetration, particles

In essence, above the ocean you can see several kilometers to the horizon under clear conditions, while underwater, even in the clearest ocean water, visibility rarely exceeds about 80 meters due to light attenuation and water clarity limits