In surfing, a wave that breaks in both left and right directions from one peak is called an A-frame.
An A-frame has a central peak with two shoulders peeling away from it. One surfer can ride the left-breaking shoulder while another rides the right-breaking shoulder, although local right-of-way rules and crowding still matter. The shape resembles the letter A when viewed from the ocean or shoreline.
A-frame waves are different from closeouts, which break across much or all of the wave face and usually offer no open shoulder. They can occur at beach breaks, reef breaks, and point breaks when swell direction and seabed contours combine favourably. The actual symmetry of an A-frame may vary from wave to wave.