A Coral Atoll

Hello All,
I am up early this morning listening to the rain pour down and the wind is blowing 25 knots. It is not a pretty day so I thought I would write a subject on Coral Atolls. They are quiet a marvel of nature.
They started life as a volcanic Island that rose from the ocean floor. When the volcano ceased to grow any further vegetation took hold and what was left was an Island just like what we are used to seeing in Hawaii. The amazing part of this evolution is that in the tropics a living thing called coral began to attach its self to the outer edges of the island. The heaviest growth being on the windward side because there is more nutrients for them to feed on. Rain fall and natural springs on the island made run off which caused gaps in the coral we now call passes. Over time erosion and just shear weight of the island caused it to settle and finally disappear. The only thing left from this timely process is what we now call an atoll. All of the coral that attached it self over time is all that was left behind. The interior of the atoll is called a lagoon. It is completely protected from the swell of the sea and can be very deep. I have seen 150 feet in some areas. The floor of the lagoon is made up of coral heads and sand. Coral has to live under the water so in some areas it will grow from the depths of the lagoon just below the surface which is why it is such a hazard for boats to navigate. When the sun is over head or just behind these areas of coral they are easy to spot because the water is so clear. Any other time or at night would spell disaster for a vessel. The passes I talked about earlier is how you enter these atolls. Some are very narrow and shallow so when the the tide floods or ebbs massive amounts of water pass through theses openings. Some currents I have seen is up to 8 knots and that is with only 8 inches of tidal difference.
Anchoring in these waters is a challenge to say the least. Near the shore the depths are manageable for anchoring, 30 to 50 feet in most cases. The problem is the bottom is littered with coral heads, most not over a foot tall but enough to have your anchor chain wrap around several times. I have been lucky so far not to get hung up but some folks I have met have had to dive on there anchors and chain to free them.(I am knocking on wood) The land mass of the atoll is widest on the windward side and is where the towns and villages are located. The widest I have seen is maybe a 1/4 mile. The height above sea level is about 4 feet.The vegetation consists of mostly palm trees and the only water supply is rain fall caught off of structures.
The fish that reside in the lagoons of the Tuamotu Atolls are unique only in this place in the world and after snorkeling in this area I will tell you, it is breath taking. Not so long ago this archipelago was avoided because of the navigation dangers but with GPS it has made it manageable to explore. You have to be within 5 miles to see the atoll by eye and I have gotten within 8 miles before the radar picked them up.
That is it in a nut shell and I hope this gives you a better understanding as to where I am in the world.


PEACE