This is arguably the single most important entry in this dictionary from a story-structure standpoint: 打ち潮 is the first Water Breathing form named on the page, full stop. It appears in Vol. 1 (p.163), during Tanjiro's fight against a demon on Mt. Fujikasane at the climax of Final Selection — before Water Wheel, before Flowing Dance, before any of the other forms in this dictionary. Everything the reader later learns about the twelve-form structure of Water Breathing is retroactively built on top of this one panel.
VIZ's "STRIKING TIDE" keeps both halves of the compound legible as English words, which matters because 潮 (shio, "tide") is doing more figurative work than a literal translation like "seawater" would capture — a tide is a directional, gathering force, not just wet. That figurative reading pays off in the 乱 (ran, "turbulent") variant seen in Vol. 9: if the base form is one directed wave, "Striking Tide: Turbulent" is that same tide breaking into chop, several strikes landing in the irregular pattern of storm-driven water rather than a single swell.
The corpus also preserves a small, telling piece of internal monologue right before the technique's debut: Tanjiro thinks "I better get this right... the first time!" immediately preceding the Striking Tide panel — a line that reads, in hindsight, as the series quietly marking its own milestone. It's the first time we see him execute one of Urokodaki's numbered forms in real combat, and the manga has him narrate the stakes of that firstness directly to the reader.