The region just beyond the breaking surf; a staging area where surfers wait for incoming waves, as differentiated from the "inside"—the broken-wave area leading to the shore. "Outside," in this usage, is synonymous with "lineup," or the Australian-derived "out the back."

"Outside" is also used to signal an approaching bigger-than-average set of waves, and is sometimes spoken or shouted as a warning to unaware surfers. To get "caught outside" on a big day of surf is to be trapped beyond the s...