In the AIDA manuals where I describe monofin swimming technique, I explain the role of the Triangle Block and the importance of seeking support with the top of that block on the water. This search for support—though visible—is not the beginning of a wave propagating backwards. It is a synchronized movement with the lifting of the fin, aiming to reposition the fin efficiently for the next propulsive phase.
One cannot analyze the hand movement in isolation. At the exact moment the hands rise, the swimmer is simultaneously repositioning the fin at the other end of the body. There is no linear descending propagation of a motor signal from the hands to the legs. What we observe is simultaneous coordination of the upper and lower body: the hands rise, the fin rises, the body rebalances and resets into Position A (see the manual diagrams), ready to project forward through the active descent of the fin.
It is this action of the fin on the water that generates a reaction force. And this is where real propulsion begins, which the swimmer directs forward by organizing alignments throughout the body.
The dolphin does exactly the same thing. When it initiates propulsion, its beak lifts—not to initiate a wave propagating through the body—but to accompany the repositioning of its tail, in a global gesture of coordinated extension. It is not a descending motor signal. It is the visible expression of tonic engagement, of longitudinal tension through the anterior muscle chain, from the tail to the head.
What we see at the head is not a “starting wave” — it is the consequence of an organized, simultaneous movement of the entire body, aimed at directing the propulsive force generated by the tail forward. In humans using a monofin, the principle is identical: the lifting of the Triangle Block is not the initiation of a wave descending through the body—it is the visible anterior part of a coordinated repositioning, preparing for the upcoming propulsion by the fin.
As the saying goes: when someone points at the moon, “those who do not yet understand” look at the finger. That is exactly what happens here: we look at the swimmer’s hands as if they were the source of the movement—as if their elevation triggered a wave traveling down the body.
But the hands are just the “finger”: a visible, partial indicator of something happening elsewhere. What we need to observe is the “moon”: the entire body organizing itself, resetting, tensing, and preparing—in global coordination—to propel the monofin in a structured and directed way. Technical movement does not originate from the extremities: it emerges from internal alignment, bodily strategy, and active transmission of force. Those who watch only the hands will never see the true movement—they’ll only see the effect, never the cause.
Conclusion:
“Undulation doesn’t exist! Not in dolphins, not in monofin swimmers. What exists is a driving force initiated from a posterior push and transmitted through a structured body.”
“Monofin swimming technique is the art of projection.”
So become artists of projection!
Now go — get back in the water. You’ve read enough for today.