Baptized by Downwellings, Washing-Machine Currents, and Near-Death Flows — Staying Calm Is the Only Way to Handle Strong Currents!

The Editor says: Every diver has been "baptized by currents" at some point in their diving career! Chaotic currents, upwellings, downwellings, washing-machine currents… all kinds of currents hide different dangers, and only by staying calm can you make a graceful exit! A big thank you to Shark Brother 吳祖祥 for sharing his experiences and making us feel as though we lived through an unforgettable dive ourselves.

"Strong currents" are the ultimate bar-talk topic for divers — seasoned veterans retell the tales with animated flair while wide-eyed beginners listen in disbelief. Over my diving life I've encountered all manner of strong currents, chaotic currents, upwellings, downwellings, washing-machine currents, and even situations that my buddies — after we made it back safely — jokingly dubbed "near-death flows." Fortunately, I've always come out in one piece. These experiences have taught me a deep respect for nature, and they've given me stories worth sharing.

Underwater current speed is measured in knots: 1 knot equals 1 nautical mile per hour, and 1 nautical mile equals 1,852 m — meaning 1 knot is roughly 0.51 m/s, and 2 knots is about 1.02 m/s. Every experience described below involved at least 2 knots.

Green Island's Sankuai Shi, Orchid Island's Sitiao Gou, and Palau's Blue Corner

All three sites feature topographic currents running at least 3 knots. The first time I encountered a strong current at Sankuai Shi, my dive buddy was gripping the reef less than 1 m away, yet no matter how hard I kicked I couldn't fight my way over to them. Battling that kind of head-on current is exhausting and futile — my legs gave out and I was gasping in under 60 seconds. I signaled my buddy to drift together, and the moment we let go and moved away from the reef's headland the current released us. We'd been separated from the rest of the group and were now surrounded by open blue water, so we deployed our surface marker buoy (SMB)s and waited for the boat to pick us up.

At Orchid Island's Sitiao Gou, while drifting along the reef wall and about to be swept into the large cavern at the end of the channel, I — back in my early days — actually pulled out a reef hook and clipped onto the rock thinking I'd shoot some photos there. The moment the hook snapped taut, the surge tore the plastic D-ring clean off my BC. That was my first, cheap BC (which is why I've insisted on stainless-steel D-rings ever since). I learned my lesson: if you want to photograph in a strong-current zone, first press your body firmly against the bottom or wall with both hands to stabilize yourself, then pull out the reef hook and clip in — only then will you have both hands free for the camera.

At Palau's Blue Corner, for example, having your reef hook ready and using it at the right moment lets you hang there like a kite and enjoy the fish aggregations at your leisure. It also helps to tie a few knots or loops in the reef-hook line so you have grip points when pulling yourself back in.

Qixing Rock, Penghu's Dongji–Xiji Corridor, and Japan's Mikamotojima

These three dive sites share a common characteristic: washing-machine currents driven by the tidal cycle. Why would anyone dive in a washing-machine current? Because that's precisely when fish school up — no current, no fish. As intimidating as it sounds, you absolutely should approach it with caution. But if your dive skills are solid, you understand the site's characteristics, and you keep your breathing slow and steady, you can weave, spin, and drift right alongside the fish — savoring the baptism amid swirling bubbles all around you.

Green Island's Gunshui Bi and Penghu's Dongji Wolf

Both sites have a gravel bottom and unidirectional strong currents of 2–4 knots. Don't use a reef hook here — even grabbing by hand requires you to latch onto solid reef, because loose gravel shifts with the flow and makes it nearly impossible to hold your position. Keep your body as close to the bottom as possible to minimize drag, and then you can relax and enjoy the Hammerhead Sharks or barracuda schools.

Gunshui Bi is a winter site — January through March — for Hammerhead Shark sightings. The northeast monsoon is fierce at that time of year, and the surface around this headland on Green Island's southeast tip is — true to the name Gunshui Bi ("boiling-water nose") — like a pot of rolling boiling water, with swells frequently reaching 2–3 m. Getting in is easy; getting out is hard. I wouldn't recommend this site to recreational divers — only the truly committed should attempt it.

On entry, everyone must jump in rapidly in quick succession and descend immediately. At 30 m there can sometimes be a downwelling that pulls you to 40 m — at which point you must pay very close attention to your pressure gauge (SPG) and decompression obligations. If you hit a downwelling, make a decisive move: kick diagonally upward (don't fight the current head-on) to escape the current zone, inform the dive guide, and end the dive and ascend to the surface. When boarding the boat, hold the ladder tight — the hull surges up and down with the swell, and a slipped grip can lead to injury. Get up the ladder quickly and cleanly. If you're not up to it, don't attempt it.

Indonesia's Komodo — Batu Balong

Batu Balong is a topographic current site. My visit happened to coincide with the tidal turnover — the moment the current reverses direction — which meant we got hit with both a powerful downwelling and a spinning washing-machine current simultaneously. One dive site, double the thrill. The roughly 5-knot current tossed all of us around quite unceremoniously; I'll be honest, it was a bit of a chaotic, harrowing exit. Thankfully all nine of us — including the dive guide — made it back safely. That's the kind of experience you only want to have once; nobody was eager for a repeat. Over dinner, when the group rewatched the footage on someone's dive computer, hearts were still pounding. We collectively named it the "5-knot near-death flow." It really was a close call. Going forward, it pays to be even more vigilant and humble. Click here to watch the clip!

The Editor's takeaway: Stay calm when you hit a current, keep your fundamentals sharp, and respect nature — that's how you stay safe!

Full article reposted from:

吳祖祥's Facebook

Further reading:

• A Marine Initiative Anyone Can Start — 吳祖祥, Shark Brother
• Diving Into Currents! What to Do When You Encounter a Washing-Machine Current, Downwelling, or 3-Knot Flow — 6 Dive Safety Tips You Need to Know
• Swept Away by a Current — How Do You Get Rescued? Choosing Among 4 Types of Rescue Signaling Devices for Both Freedivers and Scuba Divers
• 18 Common Questions from New Divers — Are You a Beginner? This One's for You!