Sunday, May 31, 2009

Just what and where are the Exumas? (long post)

I thought it would be good to provide a map of the Exumas and a little information to help everyone understand where we are and what we're up to... I should have posted this a while ago but honestly, I've kind of been learning as I go. I finally feel like I have enough of a clue to share it! Please understand that this is me talking. It's not scientific and I probably have some facts wrong. But it should help give a little better understanding :) I've taken some info from The Bahamas Cruising Guide and Stephen Pavlidis' The Exuma Guide.

The Exuma Cays (where we are):

The definition of a "cay" is: A small, low island composed largely of coral or sand. Also called "key". (thanks wikipedia). The Bahamian cays are made of limestone and coral. They are low lying - the highest hill in the Bahamas is just about 200' high on Cat Island. The cays are no more than 100' high. I can't find info on the exact size but a cay is smaller than an island. The Exumas is a chain of about 365 cays stretching north to southeast, the northern tip is about 35 miles southwest of Nassau, New Providence Island. I found a great map - see above. (I think you can click on it to make it bigger.)

All the cays we have visited, and are going to visit, are on the map except Pipe Cay and Cambridge Cay. Pipe lays just north of Sampson Cay and Cambridge is north of Compass Cay. There's a lot going on between Warderick Wells and Staniel! We have visited the northern and central Exumas, from Allan Cay to Staniel Cay. Along this route there are 4 marinas, at Highborne, Compass, Sampson and Staniel.

Flora and Fauna (what to look at and what not to touch)

The vast majority of the cays are not inhabited. Many of them are also private islands and you can't land on them. There aren't a lot of indigenous animals on the cays. There are rats, bats and hutia (look like guinea pigs), frogs, snakes, many types of little lizards (my favorite is the "curly tailed lizard") and iguanas found only on a few northern cays. There are many kinds of land and sea birds including hummingbirds, owls, thrushes, mockingbirds, bananaquits ("sugar birds"), pigeons, seagulls, tropic birds (in the spring) and osprey. We don't need to discuss the flys, mosquitoes, noseeums, sandflys, black widow spiders and scorpions. The plants are mostly cacti scrub brush, flowers and small trees. Of note is poisonwood (think evil poison ivy-like) and the small silver topped palms that seem most numerous. The epifauna and epiflora (all the good stuff in the water) is too numerous to detail here. The sharks and stingrays are pretty big and you see them from the boat a lot.

Water Depth (when to travel in shallow areas):

What the map doesn't show is that the water to the west of the islands is the Grand Bahama Bank, running right up to the south side of Paradise Island. The water here is anywhere from 1 foot to 30 feet deep. The water to the east of the Exumas is the Exuma Sound and it's up to thousands of feet deep. so depending on what direction the wind is coming from, we can go up and down on either side - getting from one side to the other through "cuts" in between the islands. In general, the bank side (west) is safer since the waves can only get so big given the shallow water. The danger lies in the very shallow areas where rocks and coral may be sitting just under the water. This is when you need to "read" the water - you can approximate the depth of the water by the color. (Martin has posted on that below) By the way, you need sunlight (and polarized sunglasses) to do this so it's not advisable to travel into shallow areas/anchorages on cloudy days.

Currents & Tides (snorkeling):

There are a lot of very, very strong currents in the Bahamas because of the shallow bank. People die here because they are swept away by currents. So you need to have a basic understanding of what they are and what they mean.

Every 6+ hours the tide comes in and out. So a huge amount of water from the ocean flows - squished through the cuts onto the very shallow bank. Then 6+ hours later it all shoots back out. This is in fact why the water is so clean and beautiful here - it's exchanged constantly and all the crude flows out to sea. All this blue and green is just what ocean water looks like - clean and shallow.

The tide is "low" twice a day and "high" twice a day. There is a 2-3 foot difference between low and high tide here. It's enough that you have to step up, or hop down, to the dock depending on the tide. It's also enough that sometimes we can't enter or exit as area unless we're at high tide because the water is so shallow.

The current is strongest right in between low and high tides. Exactly at low and high tide is referred to as "slack tide". This is the best, and sometimes only time you can snorkel some sites, especially those near cuts. This is why we snorkeled once a day at Cambridge - at high tide since it was in the early afternoon when we were there. CJ & Margie have mastered drifting with their jet ski so they can snorkel more often when there is current. We haven't figured this out with the dinghy since the engine hangs over and it's more difficult to manipulate.

Whew. That was a long one :)

1 comment:

Louise said...

Very informative! Thanks.