From Bushwalk Australia
Related to Scrambling. You literally hop, step or jump from rock to rock.
Rock hopping can be a necessity on sections of some walks, because there is no easier alternative way to progress. Part of the final climb up Cradle Mountain is an example, where the track is marked by a series of guideposts spanning many large boulders that you need to cross.
Crossing rivers and creeks, and negotating river gorges and canyons, are other situations where you may need to do some rock hopping to reach your destinaton.
Sometimes it is optional, such as rocks placed across shallow creek crossings, where using these rocks rather than wading across might only save you from wet boots. However, always check depth and strength of current when deciding whether or how to cross any body of water.
Where rock hopping is necessary, you should be competent and confident at doing it. Always undertake it with care, as it is potentially dangerous. Gaps can be wider than they appear, or rock surfaces slippery. The main objective is to avoid falling into the gaps between the rocks, in order to prevent injury and/or a soaking.