Terry Kratzer compares float-tube bass fishing to putting a puzzle together.

Fishermen are given puzzle pieces like weather, bait and wind, which challenge them to figure out how to make it all work to catch the biggest bass.

“You put the pieces together and it’s pretty satisfying,” Kratzer said.

On Saturday, about 25 fishermen took on the challenge during the Float Tube Bass Derby at Castaic Lake.

This year marked the seventh derby, an annual event organized by the Friends of Castaic Lake, said Kratzer, the tournament director.

Participants had six hours to catch the five biggest bass fish while they lounged on float tubes in the middle of the calm, pristine water.

The fish were biting, as the biggest fish caught was close to 11 pounds. The top winner lured five fish totalling close to 19 pounds.

“The conditions were very good,” Kratzer said.

Bass fishing is best from early spring through summer.

Tournament participants were not allowed the keep the bass they caught.

“All of the fish are released alive,” Kratzer said.

While most participants enjoy the thrill of catching a fish, others look forward to spending time outdoors with nature.

“It’s just peaceful,” fisherman Chris Scott, of Saugus, said.

Mike Iljin of Saugus appreciates the camaraderie that comes with float-tube bass fishing.

“It’s extremely relaxing,” he said after pulling ashore. “You meet a lot of good people.”