The rocky intertidal zone is split into vertical bands (splash, high, mid, low) defined by how long each is submerged per tidal cycle; organisms there evolved adaptations to survive repeated wetting and drying.
h_tide(t) = A * sin(2πt/T)
Stress ∝ time_exposed * wave_energy / organism_tolerance
- Tide amplitude — how high the water rises and falls each cycle; bigger swings expose the high zone longer and submerge the low zone deeper.
- Wave energy — how hard breaking waves batter the shore; high energy stresses exposed organisms even when technically "wet".
- Tide speed — sped-up playback of the roughly 12-hour real tidal cycle so you can watch multiple cycles quickly.
Watch barnacles (high zone) stay closed and pale when exposed, anemones (mid zone) visibly close their tentacles out of water to conserve moisture, and kelp (low zone) go slack when the tide drops below them — the survival-index stat drops when exposure and wave energy exceed each species' tolerance.