The only certainty about Sunday's Starbucks Kaiwi Channel Relay is that there will be new champions.

Unpredictable conditions are the norm for any paddling race across the Kaiwi Channel. But a list of new partners atop the list of favorites is adding to the intrigue for the race from Moloka'i to O'ahu.

"I think that's what makes this race a bit more interesting and fun than some of the others," perennial contender Karel Tresnak Jr. said. "There's so many variables involved when you throw two guys together."

The Kaiwi Channel Relay is for one-person canoes, but each "team" features two paddlers. The paddlers alternate in the canoe across the 40.2-mile course.

While one is paddling, the other follows in an escort boat. They switch every 10 to 20 minutes.

Tresnak won last year's race with Nate Hendricks. But Hendricks could not train regularly this year due to family commitments, so Tresnak will race with Andrew Penny.

"I'm good buddies with Andy, so we don't just do a training run and then go home," Tresnak said. "We hang out after, have a beer, talk story."

Tresnak has won the race three previous times, with three different partners. Tresnak and Penny are paddling together this year because both are sponsored by Outrigger Connection.

They will use a canoe called "Zephyr," the latest creation from Outrigger Connection.

"We're hoping for it to be rough (conditions), I think that's more our strength," Tresnak said. "It'll be a struggle for everybody if it's flat."

Kea Pa'iaina and Manny Kukulualani beat Tresnak and Penny in a relay race in March, but they will have different partners on Sunday.

Pa'iaina will team with Thibert Lussiaa, and Kulukulualani will pair with Maui Kjeldsen.

Pa'iaina said the partnerships have to do with sponsorships. He and Lussiaa both ride the new "Scorpius" canoe created by the Kai Wa'a company.

"This race is fun because you're always trying to see who's the most balanced team," Pa'iaina said. "Whenever somebody gets a new partner, you're wondering how good they're going to be together."

Maui's Kai Bartlett has won the Kaiwi Channel Relay four times, with three different partners. He, too, will have a new partner this year.

Bartlett said he's teaming with Alfred Van Gieson. Bartlett and Patrick Dolan won the event in 2005, but Dolan is currently training with the USA national kayaking team.

"Because it takes two people to do this race, it's a different animal," Bartlett said. "There are so many teams that could contend."

Race director Walter Guild said contenders from California and Australia are also expected to enter. The Kaiwi Channel is expected to be relatively calm, so the wave-catching skills of the Hawai'i paddlers could be neutralized.

Top female teams include Lauren Bartlett and Andrea Moller, Jane McKee and Jamie Kinard, Andrea Messer and Kelsa Teeters, and Donna Kahakui and Corinna Gage.

Lauren Bartlett won the female division last year with Dane Ward.

Sunday's race is one of two major relay races this month. Most of the top teams will also enter the Kaua'i World Challenge May 12.

Reach Dayton Morinaga at dmorinaga@honoluluadvertiser.com.