Participants in the Casco Bay Islands SwimRun race arrive at Cliff Island for the long course start Sunday morning.

Sarah Heck, left, a Cliff Island summer resident, talks to Marcia Sharp about the location of another island on the long course as she prepares for the start of the SwimRun.

Kelley Spencer, left, and Dennis Lucey leave Little Chebeague Island for Long Island.

SwimRun participants run along a road on Cliff Island Sunday morning.

Competitors race along the rockweed-carpeted shore of Sand Island.

A participant uses hand paddles to help speed his crossing from Sand Island to Chebeague Island.

Erin Beresini gets some help with her racing bib from teammate Jimmy Wills as they prepare to swim from Little Chebeague Island to Long Island during the Casco Bay Islands SwimRun race.

Participants enter the water to swim from Little Chebeague Island to Long Island.

SwimRun racers cross a sand bar to Little Chebeague Island.

After leaving Little Chebeague Island, SwimRun participants swim to the next island on the course, Long Island.

Erin Verkerke and Wendy Habeski come ashore at Peaks Island during the SwimRun race.

Participants climb up from the shore of Peaks Island as they approach they finish line of the Casco Bay Islands SwimRun race short course.