With wetsuits zipped up and swim caps slapped on, those practicing for the Buzzards Bay Swim took to Onset Bay to feel what it’s like swimming in open water.

The Buzzards Bay Coalition hosted the first of two open water clinics at the bay on Saturday morning. Participants learned safety tips, how the annual swimming event on June 18 will work and how to prepare for the big swim.

Coalition Event Manager Jonah Guerin led the clinic, along with Gleason YMCA aquatics director Melissa Dyer.

The Buzzards Bay Swim runs 1.2 miles from the south end of New Bedford to Fort Phoenix Beach State Reservation in Fairhaven, Guerin said. He’s expecting about 250 participants overall, and more than 200 people have already registered, he said.

Guerin detailed the support and safety personnel available during the event to swimmers as the clinic got underway.

During the 1.2-mile swim, there’ll be about 20 kayaks lining the route and 30 other boats helping as well, he said. Swimmers can also request kayak escorts to follow alongside them during the swim, which they can signal to if they’re in trouble or just hang onto for a quick breather.

This year’s swim marks the first time it’s been held normally since 2019, Guerin said, as the event was canceled in 2020 and limited to 50 people last year.

Swimmers spent the practice clinic getting used to their wetsuits and swimming from buoy to buoy in the Onset Bay. The water was calm and waves didn’t push against swimmers too much during their practice, though the open water swimming still proved quite different from completing laps in a gentle pool.

New Bedford resident Haley Synan swam in the bay during the practice clinic. She said she hasn’t done the Buzzards Bay Swim before and is thinking about signing up.

The hardest part of open swimming, she said, is making sure to look up out of the water from time to time to make sure you’re swimming straight. In a pool, you’re told to stay down and keep your back parallel with the water, she said. In the open water, shifting currents and murky water can make it harder to go in a straight line.

The Buzzards Bay Swim starts check-ins for the event at 5:30 a.m. on Saturday, June 18. Guerin said people can sign up through June 16, and those who aren’t participating but want to watch can support swimmers at the finish line in Fairhaven, where there’ll be music, food and drinks, he said.

For more information, visit the Buzzards Bay Swim website.