Monday, July 4, 2022

Underwater Color for Snorkelers

How to get the best color when you are snorkeling or taking underwater photos?

Short Answer: 
  1. For wonderful colors look at things that are close to the surface of the water on a bright clear day. That usually means shallow reefs.  On many islands it rains in the afternoon so morning can be better if the tide and wave conditions are right.
  2. Stay for a while and let your eyes/brain adjust.
  3. Get close to your subject.
  4. To increase clarity, get out of the surf to reduce particles and bubbles suspended in the water.  
  5. Do yourself and the coral a favor and stay horizontal, so that you don't stir up silt and sand.
  6. In real estate it is about location and timing.  The same applies to snorkeling.  Look for protected coves at times when the waves are small. 
Long Answer:

Objects reflect light.  The light comes from the source through the atmosphere, then reflects off the object and travels back through the atmosphere to your eye. The receptors in your eye send information to the brain for it to interpret.

Think of water as thick atmosphere making it more difficult for the light waves to travel.  By lessening the amount of water through which the light must pass, means there is more light reaching your eyes.  

More available light means more color to see.  Clear blue skies will increase the available light underwater making your snorkeling more enjoyable.  In Hawaii that means morning snorkeling is often the best.  

Closer to the fish and coral means more light reaching your eyes, brighter colors, less refraction.  The long red light rays don't travel as far underwater as the short blue light waves, so for better reds you want to be close to the service.   

Your eyes - your brain:  Color isn't just about the quality of the light reaching your eyes; it is about how your brain interprets that light.  Snorkel for a while and your brain will start putting the missing colors back into what you are seeing.  Have you ever worn a pair of colored sunglasses or ski goggles and notice that when you first put them on that the world is tinted the color of the lenses, but soon returns to normal?  You don't notice it happening.  When you remove your tinted glasses, you will notice the world has a color cast that is the opposite of your glasses.  The light hasn't changed, and you aren't looking through colored lenses, yet things appear a different color.  That also happens when you’re snorkeling for a while; your brain starts filtering out the blues and intensifying the other colors. 

Less particles in the water, means more clarity and more light reaching your eyes.  So get out of churning water, and don't churn up the water.  Places with hard-surface bottoms like lava, rock, and coral are better than fine sand that stays suspended in the water.  Light-colored, large-particle sand that settles quickly is also nice as it reflects the light making everything brighter.  Places away from a human development means less pollution, farm runoff, waste, and nutrients in the water, which means less algae suspended in the water, so better water clarity.  Even air bubbles make it difficult to see so get away from where the waves are breaking.  Areas where warm and cold water mix, or where salt and fresh water comes together also make it difficult to see, while it can be perfectly clear only a few feet away.

If the surf report says there are great waves on the beach you intend to visit, then find another beach for snorkeling.

Protected coves are great.  But even in a protected cove, high tide may mean the waves could be crashing over the jetties or coral that would normally protect a peaceful cove.  A place that had wonderful snorkeling at low tide may be just awful at high tide.  And the opposite could occur a place that is very shallow may be impossible to snorkel at low tide.
  • Tide is about the moon and gravity, so it can be predicted just like sunrise, sunset, and the phases of the moon.
  • Waves are all about wind and weather, so it has only short-term predictability based on tends and fronts, and can change quickly.
  • Windward means the side of the island where the winds are approaching.
  • Leeward means the side of the island protected from the winds. 
For best colors while snorkeling you want to be on the leeward side of the island in a protected cove, when the waves are low, when the sun is out, where there is an easy entrance into the water, and lots of coral within 4-10 feet of the surface and close to the shore, where there is heavy sand or a hard bottom, and little if any boat traffic. 

Here is where it gets confusing.  In Hawaii, they label the leeward and windward side of the island based on the most common direction of the wind.  Thus the west side is called leeward and the east side is called windward, since the wind generally comes from the east.  That is how they are labelled, not what is actually happening on the day you want to snorkel, so check the weather report!   

For example in Hawaii, "Kona winds" means that the wind is coming from the South west, which on the Big Island makes for great blue skies on the Kona side as it pushes the volcanic smog (vog) to the east, but it also brings big waves that aren't conducive to water clarity or snorkeling.  Surfers love the Kona winds.  Snorkelers do not.

If you're on the western side of the island you rather have gentle "trade winds" from the east.  This page from Pacific Disaster Center has a table that shows the months where that happens the most often.  

In Hawaii:
Check Hawaii weather, wave, and tide information before you head out.  This link also works for other place, if you change the location when you get to the website.

On the Big Island of Hawaii, we like the west side of the island, and we love the snorkeling at Two Step specifically.  Many of our photos and video are from Two Step.  

Get out of the surf. (c) 2013
Get out of the surf.  It causes too many bubbles to see well.  Swim further away from the shore.
Light refracts off the bubbles making it impossible to see what would otherwise be clear water.

Below are two pictures of the same turtle on the same day.  The first one is about 20 feet deep and the other is near the surface.  

The red color drops out with distance.  Green sea turtle about 20-30 feet down.
The SAME green sea turtle near the surface.

When underwater colors are better, besides improving your snorkeling experience, it also improves your snorkeling photos.  

Some people put red filters on their camera, but that limits the light where you need all you can get.  Others just adjust their photos in image editing software, but even then it is best to get the best colors you can in the original photo.

Photos about taken by Bill and Engela Edwards.