The first time I swam open water for real — not just wading into the ocean, but actually committing to 400 metres of freestyle in a cold Canadian lake — I thought I was going to drown. Not because the water was dangerous. Not because I couldn't swim. But because everything I had trained for in the pool suddenly felt completely irrelevant.
That's the truth about open water swimming that most training plans never bother to mention: the pool and the lake are the same sport the way chess and checkers are the same game. Similar pieces. Completely different rules. And if you don't learn those rules before race day, your swim split will tell the story.
Here's what genuinely changes — and how to get ahead of it.
The Wall Is Gone — And That's Bigger Than It Sounds
In the pool, you always know where you are. Every 25 metres there's a wall. You rest, push off, and continue. There's a bottom you can see, a lane rope on each side, and a black line showing you exactly where to go. Your nervous system finds this deeply comforting, even when you don't realise it.
In open water, there is no wall. No bottom you can touch. No line to follow. Just grey-green water in every direction, and a buoy 400 metres away that looks roughly the size of a football. The psychological shift is real, and almost nobody prepares you for it. Your pool times won't predict your open water performance, because pool times measure swimming. Open water measures swimming plus navigation, plus environmental adaptation, plus mental composure. These are trainable — but only if you actually train them.
Sighting: The Skill That Changes Everything
In the pool, you stare at a black line on the floor. Simple. In open water, you have to lift your eyes every six to eight strokes to check your direction — a technique called sighting. Done wrong, you heave your whole head out of the water, drop your hips, and add drag. Done right, you barely peek above the surface — like a crocodile — while your hips stay high and your stroke barely breaks rhythm.
It sounds easy. It isn't. Without consistent sighting practice, most beginner triathletes swim 15 to 20 percent further than the course distance by zigzagging between buoys. I know because my GPS told me so after my first open water session.
"I registered 400 metres on the course. My GPS logged 487. I'd added almost a full extra lap through sheer directional chaos — and I never noticed."
The fix is simple but unglamorous: practise sighting in the pool. Every length, lift your eyes once at the halfway mark. Build the habit until it's automatic, then take it outside.
Your Wetsuit Will Surprise You
The buoyancy of a triathlon wetsuit is remarkable. Your hips rise, your legs float effortlessly, and the sensation of swimming suddenly shifts — less work, more glide. Most swimmers are measurably faster in a wetsuit than without one. Many triathletes find the swim their strongest discipline once they adapt to the neoprene.
But there's a catch: the wetsuit restricts your shoulder rotation. If your pool stroke is built on wide shoulder turnover, the restriction will feel claustrophobic at first. Practise in your wetsuit at least three times before race day. Your body needs time to recalibrate its stroke, and you don't want that process happening mid-race when you have 40 kilometres of cycling to think about.
Cold Water and the Gasp Reflex
Even in summer, open water in Canada typically sits between 16 and 19°C. That's cold enough to trigger an involuntary gasp reflex when the water hits your face — a hardwired physiological response that your pool training, always conducted at a cosy 28°C, never once prepared you for.
The gasp reflex causes hyperventilation. Hyperventilation causes panic. Panic causes poor decisions in water. This is a well-documented chain, and it sits behind most open water anxiety in otherwise capable swimmers. The antidote is exposure and a simple ritual. Before your first stroke, submerge your face at the water's edge and breathe out slowly, three times. You're telling your nervous system — through direct sensory evidence — that the cold is survivable. Do this before every session, without exception. Within a few weeks, the gasp reflex diminishes significantly.
The Washing Machine Start
In the pool, you share a lane with two other people. In a triathlon swim start, you share 10 metres of water with two hundred. The first hundred metres look like a washing machine — arms, feet, and elbows in every direction. People swim over you. People swim into you. You will ingest lake water that is not entirely pleasant.
This is completely normal. It is survivable. But it is nothing like anything you've experienced in a pool, and panic in those first hundred metres is common even among seasoned athletes who swim well in controlled conditions. The only real preparation is simulation. Find open water group sessions. Practise circle swimming in crowded lanes. The more contact you have before race day, the less alarming it feels when it actually happens.
• Practise sighting every 6 strokes from your first open water session
• Complete at least 3 wetsuit swims before your race
• Always swim with a buddy or in a supervised area
• Carry a bright swim buoy — visible to boats, and deeply calming for your nervous system
• Do your pre-entry breathing ritual before every single session, without exception
Open water swimming is a completely different experience layered on top of pool swimming. The technique transfers — but the environment demands new skills, new habits, and a direct conversation with your own anxiety. Start those conversations early, in training, at a calm lake on a Tuesday morning with no race number on your back. Do that, and race day will feel like home.