Satellite study ranks Flamenco Beach as world’s 4th best
- The San Juan Daily Star
- 3 hours ago
- 3 min read
By THE STAR STAFF
Puerto Rico has earned a major global distinction: Beach.com has named Flamenco Beach in the offshore island municipality of Culebra as the fourth best beach in the world in a pioneering, satellite- and data-driven ranking.
Rather than relying solely on editors’ subjective selections or travelers’ preferences, the ranking analyzed NASA satellite imagery, environmental monitoring data, nearly 100,000 traveler reviews, and recommendations from leading travel experts to determine which beaches truly stand out above the rest.
“Not only do the most enthusiastic voices praise Flamenco Beach, but it also receives wide approval from the majority of visitors, making it one of the most loved and highly rated beaches in the study,” said María Pearlman, PR manager for Beach.com.
The final ranking includes 25 beaches from 14 countries and four continents.
NASA’s MODIS-Aqua satellite has been observing and recording the Earth’s oceans since 2002, capturing data on everything from the color of water to its properties. The result is a global grid dataset that contains a wealth of information accessible through Google Earth Engine.
To map each beach to the nearest data point, the study used a spatial catchment area to capture all ocean value samples within a 24-kilometer radius around each beach.
“Our main interest was to measure the reflection of sunlight on the ocean surface at different wavelengths. These measurements indicate the concentration of chlorophyll (water greenness) and the amount of light scattered or absorbed (water clarity),” said Noah Holtgraves, Beach.com’s principal data journalist. “In short, clear water allows light to penetrate further, while cloudy water causes light to dissipate more quickly.”
Since clouds and other factors affect the observations, the study used five years of averaged data for each beach.
Beach.com then used that data to determine which beaches had the clearest, bluest water. Because the method is a multi-variation analysis over several years, and because the color and clarity of the water can vary dramatically, it is far superior to any spot observation made in person. The method indicates the typical water color and clarity for any beach.
Playa Flamenco had an average of 0.225 mg/m³ chlorophyll-a (milligrams of chlorophyll-a per cubic meter of seawater). This is a measurement of microscopic algae.
“Higher chlorophyll-a values are associated with greener waters, and lower values with blue waters,” Holtgraves said. “A value of 0.225 is very, very low, which means that this beach has perfect blue water (pretty much the best).”
Flamenco had an average value of Kd490 = 0.0425 m-¹. This is the diffuse attenuation coefficient at 490 nanometers (nm), measured per meter, which describes how quickly light is reduced as it passes through water.
Low values indicate that light penetrates deeply and that water is clear. High values mean that light scatters quickly, indicating cloudy water. A value of 0.0425 is very low, indicating crystal clear water.
“In our analysis, Playa Flamenco received the Very Blue and Crystal Clear labels, which are the best in their respective categories,” Holtgraves noted.
In all, the quality of water on Puerto Rican beaches is quite high, he said.
“Playa Sucia in Puerto Rico has the worst water quality in PR (although it is still quite good),” Holtgraves said. “It had 0.353 mg/m³ chlorophyll-a [...], resulting in a very blue water color designation. It had a Kd490 of 0.0425 m-¹ [...], resulting in a very clear water clarity designation.”
It should be noted that Playa Flamenco had crystal clear water (the best label), while Playa Sucia had very clear water, which is the second best, he added.
An example of a beach with murky green water, is Mukiteo Lighthouse Beach in Washington State.
“It had 28,112 mg/m³ chlorophyll-a, earning it the Deep Green rating (the worst water color category),” Holtgraves said. “Its Kd490 was 3.017, which earned it the Very Cloudy Clarity rating (the worst clarity category).”