undulating

“It is a wonderful place, the moor,” said he, looking round over the undulating downs, long green rollers, with crests of jagged granite foaming up into fantastic surges.

The air and water were shining in the beams of the morning sun; on the shore the sailors were sitting, chatting and laughing; and at ten yards from them the boat was at anchor, undulating gracefully on the water.

Thus every now and then he saw in fancy amid the sailors, seated on a rock, or undulating in the vessel, one of the shadows which had shared his dream with looks and kisses.