The shapes of waves made by a body moving in water
A surface body raises a wave; a submerged one does not, since only the surface borders the air
The folio states a hydrostatic principle, that no water surface meeting the air ever lies lower than the sea, and then studies waves raised by moving bodies. Three small diagrams show the wave forms: a half-sphere before a moving body, a half-circle at the surface, and a spherical quarter toward the bottom. Leonardo asks why a body moving at the surface throws up a wave while a submerged one does not, answering that the surface borders the air whereas deeper water is enclosed by water above and below.
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No water surface lies lower than the sea
A general water principle opens the sheet: no surface of water that meets the air can ever stand lower than the level of the sea.
Wave forms: half-sphere, half-circle, spherical quarter
A body moving before itself raises a wave shaped as a half-sphere; on the surface the wave is a half-circle, and toward the bottom a spherical quarter. Three small ripple diagrams illustrate these forms.
Why a submerged body makes no surface wave
A body moving on the surface makes a wave, but one moving fully submerged makes none, because surface water borders the air while deeper water is bounded by water above and water below.