If the water source is placed along X-Y, as shown in the figure, which of the…

Concept

A water image is the reflection of a figure in a horizontal mirror line, such as the surface of water lying below it.

In such a reflection every point keeps its left–right position and reappears at an equal perpendicular distance on the other side of that line, so only top and bottom are interchanged.

The layout is never turned through a quarter-turn, and its left–right order is never reversed.

Application

1. The wide V that spans the two top corners and points downward reappears as a wide V that spans the two bottom corners and points upward.

2. The horizontal band line lies below mid-height in the source, so in the image it lies above mid-height by the same amount.

3. The stepped hook stays on the left of the vertical centre line and moves from just above the band line to just below it, turned upside down.

4. The tailed triangle stays on the right of the vertical centre line, and the tail that hung downward now points upward.

5. The small cross sitting on the vertical centre line moves from the lower band to the upper band.

Cross-check

Compare paired landmarks before settling on an image.

• The stepped hook must still be on the left and the tailed triangle on the right; a layout that swaps these two sides is a left–right mirror rather than a water image.

• The arms of the V must still run corner to corner along a horizontal edge; a layout in which the V opens sideways has been turned through a quarter-turn.

Therefore the water image is the layout whose upward-pointing V spans the two bottom corners, with the small cross on the centre line in the upper band, the stepped hook at the left just below the band line, and the tailed triangle at the right with its tail pointing upward.