This particular cave has an unusual effect for those who want to brave the ice-cold water. It is called the Blue Room. At the back of the main cave is a small opening into another, smaller room accessible only by swimming. Once inside the smaller chamber, look toward the main opening. The sunlight reflecting off the freshwater makes everything around you turn blue.
Viewing in the Blue Room is best during high tide as the sunlight has a narrower opening into the chamber and more of the blue color is reflected.