Loving Current Diving: Simply a Game of Hide and Seek
Part I Understanding Reef Structure
I become sad when divers recoil about diving in current. It’s such a cool place to be. There is nothing more thrilling than being out on the front end of a pinnacle with current blasting. Why? Because that’s where all the fish are!! Planktivores pull up to the dinner table by the gazillions as microscopic plants and animals fly by. Sharks ride the currents, drifting back and then peeling off only to return again. Current is the ocean’s circulatory system bringing life sustenance. It is the pump that allows life to thrive and survive in the big blue…..and it’s a lot of fun!
However, loving current is a matter of understanding it and using it to your advantage. I will never forget being a brand new instructor back in 1988 and still truly trying to figure it out. We were diving “The Elbow”, a famous site in Belize which sometimes has very strong current. We were just off the edge of the drop off tied off to a mooring line. In order to help my divers, I set up a down line off the stern and ran a second line between it and the mooring line so the divers could “crawl” down to the reef top where the current wasn’t as strong. I was so proud of myself! Once we got to the edge, and remembering that traditionally you always go up current first on a dive, we worked our way forward. Only then did I see my fellow instructor and mentor, Tom, lying on his back with his hands behind his head drifting peacefully with his divers in toe down the reef. Oh, DUH, we could have just done a drift dive! Of course, it’s so stupidly obvious now, but back then….WAY back then… I simply didn’t understand.
Most current is tidal so you can often choose when is the best time to dive the currents of a particular reef. Obtain local knowledge and tide charts to understand when and how strong currents will be on any given dive and when the currents will turn. Hire a local guide if you don’t completely understand the currents of an area.
Current 101- There are three sections to understanding current 101 which I will discuss in three separate posts.
Part I ~ Learn the structure of the reef and how the current moves around it.
Part 2 ~ Learn how best for YOU to maneuver in the current relative to the reef.
Part 3 ~ Learn tips to prepare yourself and your buddy for diving, and staying together in the current.
Here are some of the major reef types you might be diving and how current is affected.
Walls and Slopes ~ Parallel
Walls and slopes along or parallel to the current line. If you are diving a long wall or slope, often tidal current simply cruises down the length of the wall. If the wall has cuts, it will probably also eddy. The current will spin in the cut like wind swirling in the doorway of a large building. Current strength will appear to dissipate as you move off the reef as there is less affect of the reef on the water movement.
Walls and Slopes ~ Perpendicular
Walls and slopes perpendicular to the current line. Sometimes, current runs perpendicular to a wall or slope and comes straight at it. In this case, the deeper you are the less strong the current. As the current hits the slope, it flows upward. As you become shallower, the current will have a tendency to push you up and over the top of the reef. As the amount of water overhead becomes less the water is “squeezed” and the current will become stronger.
Pinnacles. Pinnacles in current are great because there is a “front” and “back” side to them. Current will hit the front side and split around the pinnacle. Often there is a slack spot at the base of the pinnacle without current on the front side. As well, depending on the size and shape of the pinnacle there can be “dead” spots along the sides of the pinnacle as well. The current will be the strongest shallow and at the front point of the pinnacle.
Patch Reef/Coral garden/Flat Reefs.
Cuts and Channels
Notice what grows in cuts and channels. It is either very little due to large current flow or lots of soft corals which thrive in the current. Here you can find some of the strongest currents as the water is forced through small spaces in the cut during strong tidal flow. Be sure to consult tide charts before attempting channels and cuts with strong currents.
Ok, now you understand the 101 of how currents flow around the major types of reefs diver’s dive. In my next post we’ll talk about how YOU maneuver around in these currents to enjoy the best the site has to offer.
To Your Adventures!