The waters around the Bahamas are light blue because the water is shallow. The blue color comes from the absorption of red and green light wavelengths by the water. The blue is reflected to be received by your eyes. The light blue is a response to sunlight reflecting off the sand and corals on the bottom.

The breathtaking turquoise color of Bahamian water is a result of geology, shallow depth, and pure white sand. The islands sit on the "Great Bahama Bank," a massive underwater plateau. The seafloor here is composed of fine, white calcium carbonate sand—remnants of ancient coral and shells—which acts as a giant mirror, reflecting sunlight back up through the water. Water naturally absorbs red and yellow light while scattering blue and green; in the shallow depths (averaging less than 10 meters) of the Bahamas, this effect is amplified by the bright seafloor, creating that luminous sapphire-turquoise hue. Furthermore, the Bahamas lack major rivers that would dump murky silt and sediment into the ocean, keeping the "turbidity" (cloudiness) extremely low. This clarity allows sunlight to penetrate deep and bounce off the white sand without being filtered by mud or organic matter. The presence of the Gulf Stream also helps by acting as a natural barrier that sweeps away darker Atlantic waters, ensuring the lagoons remain some of the clearest and most vibrantly colored on the planet.