Diving in currents can be an exhilarating experience, watching the underwater world drift past effortlessly. Some of the most alluring dive destinations (like Galapagos and Komodo) boast moving water that not only add to the exhilaration, but are the source of the reefs’ diversity, vibrancy and health. Currents carry vital nutrients to corals and create a convenient conveyor belt of prey for ocean predators like sharks and large pelagic fish. But diving in currents demands respect, proper technique, and a calm, collected approach to stay safe and make the most of your experience. These are some tips and safety precautions to help make your next drift dive safer and more enjoyable.
Preparation = success
Before even hitting the water, a good dive plan is essential. Research the site, talk to local dive operators, listen attently to your divemasters’ briefing and understand the expected current conditions. A current check by your divemaster and/or boat captain is a sign of competency and responsible diving practices (check out my tips for selecting a dive operator). This is typically done in two steps.
Visual Check - Surface conditions give clues to what the current is doing underwater. Patches of irregularly smooth water typically denote a current being pushed to the surface by underwater topography. By watching how water moves past fixed objects like rocks or buoys you can estimate which way and how fast a current is moving. A good pair of polarized sunglasses helps immensely with this task. I have always trusted Costa del Mar for superb lens quality and polarization ability (I’m inseparable from my pair of Costa del Mar Rincons when I get on a boat).
In-water Check - This step helps clarify the characteristics of the current. It’s done by lowering a weighted line and watching which way it gets pulled, or by getting in the water and watching either the bottom or any fish life in the water column beneath you. Generally, fish will swim into a current, so if you see all the fish facing one direction below you, it’s a good bet that there’s a current moving in the opposite direction that they’re facing.
Notice all of fish in this image facing the same direction? This is a good indicator that there is a current moving from right to left through the frame.
get in and get down
Strong currents may require a negative entry—descending immediately without a surface pause—to avoid being swept off the desired point-of-interest. This is a good thing to practice before actually diving in a current. By completely deflating your BCD, making sure you’re gear is dive-ready, and performing your buddy check prior to splashing into the water, a negative entry helps you descend to the right spot.
If possible, use an anchor or mooring line to descend. Discuss entry and exit points, signals, and contingency plans with your buddy and divemaster.
Prim, Trim and proper
Once you’re in the water, the key to diving in currents is minimizing resistance. Keep your body horizontal and as streamlined as possible—arms tucked in, legs extended. Practice neutral buoyancy and don’t hesitate to adjust throughout the dive. Think of yourself as a glider, not a parachute. Excessive movement will waste energy and increase drag, making the current feel stronger than it actually is.
Work Smarter, Not Harder
Swimming against the current is a battle you won’t normally win. Instead, use the terrain to your advantage. Stay as close to the bottom as feasible without risking surpassing your no decompression limits or coming in contact with any live substrate like coral or seagrass. A good rule of thumb is that the closer to the bottom, the weaker the current.
If necessary and permitted, use reef hooks or grab onto dead rock (never live coral!) to stabilize yourself while observing marine life. A pair of neoprene gloves can come in handy to reduce abrasion on your hands. When moving, use a slow, steady frog kick or a modified flutter kick to maintain efficiency without overexerting yourself.
Go With the Flow
Drift diving is one of the best ways to experience a current dive—letting the water do the work for you. Maintain neutral buoyancy, adjust your trim, and let the current carry you along. I like to drift perpendicular to the direction of the current, facing the reef so that the reef, the divemaster and my dive buddies are in view all at once. This positioning also allows you to make a direction change quickly should you need to catch up to the divemaster or swim into the current.
Upon encountering something you’d like to spend more time with, turn and kick up current and keep as streamlined as possible to extend your viewing opportunity.
Ascending Safely
Two divers prepare to launch a DSMB (delayed surface marker buoy) to alert the dive boat above to their location.
When it’s time to ascend, it’s crucial to do it properly. Ascend at a controlled rate—no faster than 60 feet per minute, and preferably slower. Although somewhat counter intuitive, make sure to deflate your BCD before ascending. By maintaining negative buoyancy you ensure that you are controlling the rate of your ascent with your kicks rather than letting the air in your BCD float you to the surface. I’ve written about the importance of safe ascents in my blog on DCS. Practice using an SMB (surface marker buoy) and keep one with you to release before ascending so the boat crew can track your position. I carry an orange APEKS DSMB with a 100ft reel of line, but even a cheapie safety sausage will do the trick. If the current is strong at the surface, the boat should deploy a tag line to prevent drifting away while waiting to board.
Final Thoughts
Current diving is one of the most thrilling aspects of scuba diving, but preparation and proper technique make all the difference. Stay calm, stay streamlined, and work with the current—not against it. With practice, you’ll learn to ride the underwater superhighway with confidence and ease. Safe diving!