Try out kayaks and stand-up paddleboards on the water, run an obstacle course and learn about sports and recreational activities at Seattle Parks and Recreation’s Big Day of Play on Saturday at Magnuson Park. There’s a 3-on-3 basketball tournament (by preregistration), Kid Zone activities and free, fitted bike helmets for kids, golf and yoga information and activities, performances including Recess Monkey and School of Rock, a dog-agility course and more for all ages, 10 a.m.-3 p.m. Saturday, Magnuson Park, 7400 Sand Point Way N.E. Seattle; free, www.seattle.gov/parks/healthyparks/big_day.htm,