Imagine doing yoga without ever finding stillness in a pose. Imagine your downward dog is always walking, rocking, swaying to and fro. Imagine that your greatest accomplishment during practice is holding chair pose without doing an accidental somersault. Imagine going back to the beginning after you’d been advancing through a practice for 15 years.

Practicing yoga while sailing the big blue sea probably feels similar to doing yoga in a dryer set on “tumble.” It requires a whole new level of zen. Even though attempting yoga on a bouncing boat can be extremely frustrating in itself, the alternative would be even more frustrating: I would be a horrible crew member and unhappy human without my practice onboard. Yoga helps me breathe through the ocean’s endless time. It centers me within an incomprehensibly vast space.

Continuing to practice at sea unveiled new wells of patience with myself, and forces me to accept the limits imposed by the watery world around my floating home. The worst sacrifice: no headstands. Bridge and downward dog are about the only safe inversion in 15-foot seas. Forward bends and child’s pose round out the blood-to-the-head poses. Second saddest sacrifice: no balancing poses … at least in the traditional sense.

In reality, every movement all day long on passage is its own balancing pose. Even the simplest yoga asanas requires 100 times more forcus on balance than they do on land. The rolling swells require at least 3 points of contact at all times, but often 4 points is mandatory. Triangle becomes a tangle as the stern dips 20 degrees left, then right, then flings left again. Warrior series are possible only if one hand maintains a death grip on a nearby lifeline, which limits their fluidity and mobility. A simple sun salutation is an ab-busting, shoulder-wrenching, mind-over-matter exercise as my ass becomes a pendulum threatening to overtake my anchor points on deck. I’ll never roll my eyes again when an instructor says to “root through my feet” or “feel grounded in the pose.”

Luckily, yoga at sea provides plenty of benefits, once I was ready to receive them. Even as a moving boat drastically narrows the diversity of available asanas, it doubles the amount of time I practice. Each morning I move through sun salutes to energize and elongate. Long, comforting stretches settle my mind and bones during the 12:00 to 2:00am night watch each evening. I have a newfound affection for the hatha and yin yoga poses I used to shun in favor of faster-paced flow. The rocking space lets me connect truly and deeply to each asana.

I still long for the day when I can cement my feet — and my head! — to a substrate that stays still. Meanwhile, yoga reminds me that my body is still my own, though it feels lighter and smaller beneath the uncontrollable wind and waves. It keeps me saner, calmer, quieter, and more real during the surreal journeys across the sea.