Current events, Part 2: Drift dives and thrill rides

In the previous post, I talked about the kinds of currents that divers encounter in the ocean. I ended with the statement that some currents are gentle, while others rip along with incredible force. Some of our most memorable dives have been in currents. Allow me to reminisce about some of the those.

After logging several thousand dives over a period of decades, as we have, you would think all those dives would blur together in memory. Indeed, some do -- yet many individual dives stand out clearly in our minds, almost as if we had done them yesterday.

Memorability often hinges on having seen something unusual or special -- a rare species, for example, or a first encounter with a big animal like a whale or a large shark. Memorability also is sealed by emotions felt during a dive, especially emotions that are fueled by an adrenalin surge.

Drift diving at Ras MohammedDiving in currents often takes the form of a planned 'drift dive.' Divers enter into a known current, and ride it downstream. This is a very pleasant way to do some underwater sightseeing, because you can cover more territory with less effort. It's a lot fun -- as long as you have an exit point picked out downstream, or have a boat following your bubbles, ready to pick you up when you surface.

Drift diving in a mild current requires that divers still swim a bit, albeit with gentle assistance from the current. In a strong current, however, swimming is unnecessary. Instead the diver focuses on steering, mostly by using his fins as a combination rudder and dive plane. That's what Jerry is doing in the photo on this page.

If you look carefully at the photo, you'll notice that Jerry's bubbles are leading him (along with a trio of friendly jacks). The bubbles are being pushed ahead by a strong current that is also propelling Jerry, excusing him from having to kick.

The strongest current we have ever ridden as a planned drift dive was in a channel along the western edge of Bunaken, a small island off North Sulawesi, Indonesia. There, a drift dive in a very swift current became a high speed thrill ride. The current was so strong that we had to assume an unusual posture, just to keep from tumbling. Instead of facing down-current in a prone position, using fins for steering (as in the photo), we had to ride along sideways in an upright position, arms folded across the chest, with our legs straight down and crossed at the ankles, using our fins as a sort of keel for stability. We whizzed along so fast that taking photos was out of the question, but it sure was one heck of an exhilarating ride. We surfaced next to our chase boat whooping and cheering and high-fiving each other.

Currents sometimes run in layers. For example, an outgoing tide may create a current heading seaward, yet if there is a strong onshore wind, it may create a layer of surface current heading toward shore. Throw some underwater topography into the mix and even stranger things can happen.

One of the craziest dives we ever did involved multiple currents in multiple layers. When I say it was a crazy dive, I mean crazy in every sense of the word. The conditions sure were crazy, and maybe we were a little crazy for doing the dive, too, but I must admit we executed it just about perfectly. Let me see if I can explain.

We were on a live-aboard dive boat in the Red Sea, visiting dive sites near the the Sinai peninsula. Aboard the vessel were a small handful of relatively new divers, and another group of five very experienced divers with advanced training who were old hands at Red Sea diving. We were a part of the latter group. Because we were already very familiar with the dive sites there, and because we were all divemasters or instructors in our own right, we were left alone to manage our own dives, freeing the boat's lone dive guide to tend to the newbies.

Late one afternoon the boat brought us to Ras Mohammed, at the tip of the Sinai peninsula. Ras Mohammed is actually a complex of dive sites. The best known sites are just off the cape at the tip of the land peninsula, where a large pinnacle rises from the sea floor hundreds of meters down. At a depth of about 25 meters, the pinnacle splits into two, with a sort of plateau running between the pinnacles and then toward the land. The eastern pinnacle is known as Shark Reef, and the western one is called Jolanda Reef. Can you picture that layout?

As the boat approached Ras Mohammed, the two groups planned their respective dives. Expecting a bit of current running westward over the plateau, the dive guide planned to lead the 'baby divers' (as they were always called) along the eastern edge of the plateau to a site known as Anemone City. Our advanced group decided to enter the water at the same spot, but to drift with the current over the plateau, then swim between the two pinnacles and around the seaward side of Jolanda Reef, the more distant of the two pinnacles from our entry point.

We arranged for Armando, the boat's Italian deckhand, to pick us up in the boat's tender at a mooring buoy on the far side of Jolanda Reef exactly 50 minutes after we entered the water. Being a safety conscious lot, we even reviewed an alternative plan with the boat's crew, in case something should go wrong. We were all equipped with 'safety sausages' -- bright orange tubes (flattened, rolled up, and carried in our pockets) that turn into 6-foot high marker buoys when inflated at the surface. We showed them to the crew, telling them that if we could not make our rendezvous point for any reason, we would surface and inflate these markers, and wait for pick-up.

Our group entered the water first, followed by the baby divers and the guide. We immediately noticed that there was a surface current running in the opposite direction from what we had expected. The divers in our group signaled to one another to descend, and sure enough the current was running in the expected direction a few meters down. We pressed on.

By the time we got to the spot between the two pinnacles where we needed to make our turn to go around the seaward side of Jolanda the current was raging, but at least it was going in the right direction. Sort of. Because the current split at the pinnacle, the current was actually pulling toward the open sea at the side where we intended to pass. We needed to hug close to the pinnacle in order to round it, and we had to kick with all our might for a minute or two just to steer through the turbulence. Once we rounded the corner we had a free ride with the current again pushing us along effortlessly.

All of this took twenty minutes. We now had a half hour to kill before our pick-up. We poked along, back and forth across the face of the pinnacle, taking in the scenery and peeking into holes and on ledges as we ascended very, very gradually. As we approached 10 meters of depth, we encountered another current that pushed us seaward. We swam out of it in an arc, back toward the pinnacle, and again ended up in the pretty coral garden under the mooring buoy that was our target. Near the end of our allotted time now, we stayed there.

We heard the putter of the little outboard engine on the Zodiac as it approached. The deckhand shut off the motor and tied up to the mooring buoy just as the five of us popped our heads above the surface alongside the little rubber boat. Armando yelled as if he had seen a ghost, and blessed himself several times. As we hauled ourselves aboard, he kissed each one of us on the cheek. Clearly he was glad to see us!

Unbeknown to us, it turned out that the guide and the baby divers had aborted their dive after less than five minutes because they could not handle the surface current. The guide told the crew they had better start looking for us right away, because there was no way we would be able to make it to the mooring buoy as planned. They all had spent the past 45 minutes scanning the horizon, watching for our orange signal sausages, fearing we had been swept out to the open sea. They didn't see us, of course, because we had continued our dive as planned.

Armando had brought the Zodiac to the rendezvous point at the mooring buoy on schedule, but apparently hadn't really expected to see us. When we surfaced just when we said we would, just where we said we would, no one could believe it. When we got back to the boat everyone cheered. They treated us as if we really had been lost at sea and recovered, whereas the five of us felt we had simply "planned our dive, and dived our plan." Only in hindsight did we start to believe that maybe we had been a little crazy to continue in those crazy conditions.

Next time: A final episode on currents (at least for now).

5 comments:

  1. Until now I had never given a lot of though about currents in an ocean.

    And thanks for the explanation in the previous post for my question.

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  2. I have enjoyed your posts on the currents - and have learned a lot too!

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  3. Hi Mike and Kathy -

    Diving in currents can be fun and even exciting, but as you'll see when you read the upcoming post, currents also can create some very unpleasant situations for divers.

    Bobbie

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  4. I bet those were some thrilling rides Bobbie, where can I sign up?

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  5. Bernie, before you sign up you had better read the next post!

    Bobbie

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We welcome your comments and invite your questions. Dialogue is a good thing!

Bobbie & Jerry