Current Affairs: How Water Moves
- Chetana in conversation with Sahil Khanna
- 2 days ago
- 9 min read
Updated: 11 hours ago
The Maldives Story
We were sitting together by the sea in Amed, Bali, watching the sun set behind Mount Agung. Finally, we were on our long-awaited trip to Indonesia - the one Sahil, John and I had been planning for years. As the sky shifted to crimson hues, our conversation drifted towards ocean currents - the kind we would soon have to mentally prepare for and physically gear up to face on our upcoming dives in Komodo National Park. Here is the thing though, more often than not, conversations about currents and diving usually revolve around how stressful, inconvenient, best avoided they are - sobering to fight against and throw expletives at!
Speaking with Sahil about currents was different. His enthusiasm was infectious - it made you so curious that you would want to jump into the water immediately to feel what he was describing.
In riveting detail, Sahil explained how ocean currents are an absolutely fascinating phenomenon. The thrill of experiencing their force and understanding the crucial role they play in powering the oceanic system — is mind-boggling. But most of all, to Sahil, currents are a complex set of puzzles he could happily spend his entire life trying to solve!
We ended up having several long conversations about them during our travels in a small corner of the Coral Triangle. Here are a few snippets that really stayed with us.
Chetana: How would you explain currents to people who have never experienced them before?
Sahil Khanna: I usually start by explaining why currents matter. They carry nutrients that nourish the reef, and bring in food that gets the small fish moving. When the little fish get active, the slightly bigger ones that hunt do too, and the whole cycle comes alive. I tell people that the stronger the current, the more life and energy you’ll see in the water. Once you learn how to dive with the current instead of fighting it, you stop being afraid of it and start to enjoy it.
CP: You have been working as a SCUBA dive instructor in the Maldives for over a year now. I remember you were really looking forward to diving in those currents. What’s makes the Maldivian currents so special?
SK: Before coming to the Maldives, as a dive professional, I really wanted to:
A. Understand currents.
B. Be able to handle myself in them.
C. Be able to guide and take divers through them.
The last place I experienced any kind of current was at the outer sites in Havelock (Johnny’s Gorge and Jackson’s Bar) in the Andaman Islands. Back then, I used to pray for a no-current dive whenever we went to those sites. I definitely wasn’t comfortable taking guests out in strong current conditions. But now, after diving in the Maldives, I actually get excited when there is a current! I think I’ll be more confident, and maybe even dive the sites in the Andamans a little differently the next time.
Currents in the Maldives are special because they are not very predictable — and that’s exactly what I love about them. Every day brings something new. You can make a rough estimate based on the season and a few other factors, but you only really know what you are dealing with once you reach the dive site and jump in for a current check.
For example, in Komodo, you can usually predict the strength and direction based on the tides and the moon phase — neap tides mean mild currents, while spring tides mean rippers. But not in the Maldives.
CP: What are some of the types of currents you have experienced during your time in the Maldives?
SK: The Maldives has all sorts of currents. There’s the channel current, which moves either in or out of the atoll, and the oceanic current, which flows along the outer walls of the atoll.
Where these two meet, the washing machine currents can form. Sometimes, when the current hits a rock formation at an odd angle, it creates an eddy, where the flow suddenly shifts in a completely different direction from the rest of the dive site.
When the outgoing current is strong, it can create a down current at the edge of the wall. When the incoming current is strong, it can form an upward current along the wall. So, you get everything, it all depends on the topography of the dive site and the strength of the current.
CP: What's the best way to dive in a current, in your experience?
SK: It depends on a few factors: the topography of the dive site, the best position to be on that site, the depth, and how long you plan to dive.
The general rule: don’t go against the current. That’s what keeps the dive easier and more enjoyable.
If it’s a pinnacle dive, the goal is to enter at the split - the point where the current hits the reef. Depending on how strong the current is, you take the boat a bit farther into it so that when you jump, you drop right onto the center of the pinnacle.
For example, if the current is coming from the east and moving west, you drive the boat east so that when you enter, the current gently carries you onto the reef. You stay at the split for as long as you can, that’s where all the action happens: sharks cruising, fusiliers, bannerfish, triggers — everything.
When you’re done, simply drift with the current to the back of the pinnacle, where it’s more sheltered, do your safety stop, and end the dive. Even at the split, you don’t actually feel the current that much- it’s surprisingly comfortable.
If it’s the corner of a channel dive, you need to account for two currents - the channel current and the oceanic current - which can move perpendicular to each other. In that case, you plan your entry so the current carries you to the area with the most marine life.
In both situations, you don’t fight the current, you either drift with it or hold your position. You can use reef hooks or just grip bare rocks and simply let the show come to you.
What stresses people out is having
to swim against it. That’s not fun - it’s tiring and burns through your air faster. That’s why, in the Maldives, dive pros always do a current check before every dive to make sure we don’t take guests somewhere they’ll have to fight it.
CP: How does one prepare for a strong-current dive?
SK: Take it step by step; do not jump straight into the rippers. Start with dive sites that have mild currents, build your confidence, then move to more challenging ones.
Listen to the briefings carefully and have any doubts cleared before entering the water. Stay close to your guide. Most importantly, let your guide know if you’re not confident about diving in currents. We really appreciate it when guests tell us beforehand, because then we make sure to keep an extra eye on them.
CP: From your observations, how does marine life deal with currents?
SK: It’s fascinating to watch how marine life behaves in currents.
On calm days, you’ll see large schools of fish such as red snappers and midnight snappers drifting in the blue, moving in any direction they like. Then you come back the next day when the current is strong, and all those same fish are huddled against the reef, facing the same direction.
You will see turtles flipping around, trying to steady themselves, taking little breaks behind rocks or coral bommies. Sharks love it though; they cruise effortlessly, drifting in the current.
Trevallies turn their bodies sideways to cut through the water, and when they are schooling, the sunlight reflects off their flanks so they seem to glow. Rays move even more gracefully. Eagle rays glide against the current with speed, barely flapping at all. They look like eagles in the wind, and perhaps that is how they got their name.
Divers often use fish behavior to read the current. The closer the fish are to the reef, the stronger the current. The direction they face shows you which way the current is moving.
CP: Do you find that marine life tends to be more active when the currents are stronger, or is that too much of a generalization?
SK: Yes, marine life is definitely more active when the currents are stronger. I’m not entirely sure why, but I’ve noticed it consistently.
Now that I think about it, maybe it’s because everything gets pushed closer to the reef, so we see more and it just feels more active.
The type of current also makes a big difference. For example, at one of our sites in the Maldives, when we have an outgoing current (water moving from inside the atoll to outside), it’s plankton-rich, so visibility drops, but mantas show up in large numbers. You don’t see many sharks then because they prefer clearer water.
When the incoming current arrives (the opposite direction), the visibility can reach up to 50 meters, and suddenly you see sharks everywhere. It’s the same site, but with a completely different vibe.
CP: Can you describe your most memorable ‘currenty’ dive to date? Where was it?
SK: We had gone to a dive site called Shark’s Tongue, and I had two open-water students completing Dive 3 of their open-water course.
The other dive pro jumped in for a current check and came back saying it was mild and flowing in the perfect direction for that site, so I was happy. I drove the boat to the jump point, we entered, and off we went. The students were doing great — exactly where they needed to be, following instructions, and looking solid.
Then suddenly, I felt the current getting stronger. I spotted a marker on the reef I usually use to gauge when the reef is about to end and realized it had only been 15 minutes! If we kept going, we would finish going around the entire site in 30 minutes. So, I found a rock and got my students to hold on so we could enjoy the reef for a bit.
Before I knew it, the current was getting stronger and stronger until we were literally like flags underwater, regulators purging on their own, bubbles everywhere — absolutely wild. It became so strong that sand started lifting off the reef, reducing visibility. We could see the fish struggling; one turtle was barrel rolling out of control, bumping into the reef repeatedly. Even the sharks were losing control. Everything that had been out in the blue was now pressed against the reef, looking for shelter. It was chaos, but amazing chaos.
I looked back and saw my students grinning, having the time of their lives, and I was just happy.
Then I decided to let go, and what would normally take 15 minutes to cover, we did in two. We literally flew!
At the end of the site, I decided to move shallower and go on top of the reef, which is normally a calm, sheltered spot for a safety stop. But not that day. Suddenly, it started pulling us into the deep. We had to fight and crawl for about 30 seconds, and then, for the next 30 seconds, it switched and carried us exactly where we wanted to go. This back-and-forth continued for a while.
When I launched my surface marker buoy, I realized it was drifting one way while I was going the other. And then, just like that, everything stopped. Absolute stillness. The ripping current disappeared completely. It was an eventful dive, to say the least.
CP: Do you feel you’ve learned everything there is to know about currents, or do you still have unanswered questions?
SK: Nowhere close. There is so much happening, and it is always changing.
I have been trying to figure out patterns, and I have even started keeping a logbook just for currents, noting conditions and other details to see if anything repeats. No luck so far.
In places like Komodo, the currents are a bit more predictable because they follow the tides, so you can roughly gauge direction and strength. It is the same in the Andamans, where I had figured out a few patterns. For example, Johnny’s Gorge would always have a strong current when moving from high to low tide during neap tides, and a milder one from low to high during spring tides.
But the Maldives is something else entirely.
Last year, we had outgoing current until the end of November. This year, we randomly had a small reversal in October; suddenly, it was incoming for a while before switching back. It is totally unpredictable.
CP: From your own experience or from speaking with others, do you think the currents in the Maldives are changing as a result of climate change or ocean warming?
SK: In my relatively short experience of a year here, I have definitely noticed some changes, although I am not sure whether they are due to climate change, ocean warming, or simply natural variations in current patterns.
Perhaps currents do not really follow the neat 12-month schedule that we humans like to think they do.
About the author
Sahil Khanna is a dive instructor from India, currently based in the Maldives. He is fascinated by diving in currents and hopes to see a hammerhead shark one day. He loves underwater photography and playing golf.
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