A submarine viewed from above, partially submerged in water, with two torpedo tubes visible on its side and arrows indicating the direction of movement. The submarine’s conning tower is visible, and the hull is shown in cross-section revealing internal compartments. The water surface is depicted above the submarine, with a small patch of sky visible in the upper left corner. The illustration is rendered in a watercolor style with earthy tones and clean outlines, characteristic of David Macaulay’s architectural and mechanical diagrams.