“More than 80 choreographers and dance companies, of just about every artistic persuasion and level of experience, will perform in 15 different programs in this sprawling but oddly cozy annual extravaganza. Saturday from 2 to 4 p.m., 5 to 7 p.m. and 8 to 10 p.m., at the John Ryan Theater, 25 Jay Street, Dumbo section of Brooklyn; Sunday from 1 to 3 p.m. and 4 to 7 p.m. at the Empire-Fulton Ferry State Park, on the Brooklyn waterfront between the Manhattan and Brooklyn Bridges; (718) 855-8822, whitewavedance.com; free.”