A beautiful feature of the coastal waters of Hawaii is the amazing blue color of the water. Hop on the Hoku Nui for a snorkel or manta ray tour and enjoy the pristine waters off the West Coast of this magical island.
There are some reasons that Hawaii seems to have more blue waters than other locations. With visibility of up to 200 feet the waters are very clear and blue. According to Chrissie Smuts for Coastal Dream Life, one of the reasons for this is when sunlight enters the water it absorbs red wavelengths and scatters the blue wavelengths which makes the water appear more blue. The lack of sediment and algae also helps to keep the water clear.
Phytoplankton is a microscopic marine alga that goes through the process of photosynthesis which creates half the oxygen for humans. As algae absorbs the red and blue wavelengths, it reflects green wavelengths into the water. The rule of thumb is that oceans with more algae appear greener and those with less algae appear bluer. Hawaii has less algae and other organisms such as zooplankton and other particles which is one reason why the water appears bluer.
Other reasons for the blue appearance of Hawaii’s waters are:
The warmth of the tropical waters is conducive to less chlorophyll which reduces the algae content making the waters bluer. The Hawaiian Islands are surrounded by coral which protect the shoreline from energetic waves. The sediment in Hawaii is heavier than in other oceans so is not easily stirred up and keeps the blue waters clear.