Read this excerpt from a play.

(the scene begins aboard a whale-watching boat. many students slouch on benches, others lean lazily on ferry railings. a few students thumb through shiny brochures, shaking their heads and grumbling quietly.)

gregor: this is not what i expected.

omar: yeah. whale watching? more like wave watching. what a rip off.

(omar turns to a whale picture in his brochure and holds it up to the group. a few heads nod, but it is not the reaction he hoped for. he retreats to a quiet bench. a splash a few yards out in the water stirs the group, and many rise.)

gregor: that’s more like it. guys, c’mere. look here, just below the surface. (students lean forward, many pull phones and cameras from their coat pockets.)

which setting detail advances the action of the scene?