Young swimmers kicked and paddled around Last Chance Splash Waterpark & Pool Monday, oblivious to the water raining down on their mothers lounging poolside in sunhats.

With temperatures clipping the 80s and clear blue skies, soaked children were nearly dry by the time they reached the end of the line for the multi-story waterslides.

A group of 12-year-old boys took turns soaring off the diving board, arms out, bellies stretched tight. And then that telling slap of skin on the water.

“That hurt. Oh man. That hurt.”

The city-owned pool and water park drew about 300 people Monday for the first day of the season, aquatics program manager Todd Wheeler said.

In addition to water polo matches and aerobics classes, the pool is offering Starfish Aquatics Institute swimming lessons, a nationally known teaching program, for the second year.

Wheeler said a new online registration system for swim lessons and day passes has them expecting higher turnout this year, with most of the first round of month-long lesson programs already full.

Morning and evening group lessons are offered for children as young as 6 months old, which focus on helping toddlers become comfortable in the water, according to the pool’s website. Also offered are classes covering drowning prevention, self rescue and advanced stroke proficiency.

Although fewer teenagers and adults sign up for lessons, Wheeler said the pool offers one-on-one private lessons on an as-needed basis.

Lap swimmers can get started as early as 9:30 a.m. on weekdays this summer, while the rest of the waterpark opens at 12:15 p.m. for open swim, and closes down at 7 p.m. Weekend hours are a bit narrower, with all activities open from 1 to 5 p.m., with the season wrapping up Aug. 19.