Silverdale’s Bruce Waterbury will turn 55 years old on Sept. 17. His daughter, Kristi Balant, will turn 28 on Sept. 13. But the dad-daughter duo has special plans for a joint celebration on Sunday, Sept. 14.

They’re going to swim from Alcatraz Island to San Francisco.

“When I tell people about it, they tell me I’m crazy,” said Waterbury. “Many people believe that you can’t swim Alcatraz because of the extremely cold, choppy water, the strong current and the sharks. Many people believe this because of the movie ‘Escape From Alcatraz.’ Obviously, it can be done and many people do it each year.”

According to his daughter, the two planned a birthday trip to visit Alcatraz, and the swim came about a bit later.

“Dad’s always had an interest in Alcatraz,” Balant said. “He’s a history buff. So we planned a birthday trip to go see it and when I got looking into it, I found out there was a swim that weekend. So I asked him if he wanted to do it.”

The pair have been training for since April, first in swimming pools and then in nearby lakes — Wildcat Lake, Haven Lake, Wye Lake and Horseshoe Lake.

Balant didn’t think twice about the swim from Alcatraz to San Francisco. She was a competitive swimmer in high school when she attended Central Kitsap High. She was a member of the Olympic Aquatic Club and shared lanes with Nathan Adrian.

Her father, on the other hand, did think twice.

“I’ve swam Lake Washington,” he said. “And I swam on a high-school team back in Iowa. I wasn’t sure about this one, but I don’t like being the cheerleader. I like being in the game.”

So the next day he told her he was going to do it.

“Some people might think I’m a foolish old man,” he said. “But it gives me great pleasure to share experiences with my daughter.”

In fact, they’ve done many dad-daughter dates before, including a trip to Graceland for his 50th birthday, and a night of “ghost hunting” at Bremerton Community Theatre.

“It was just us two,” he said of the theater. “We got our pop and popcorn and watched her favorite movie, ‘The Ghost and Mr. Chicken’ in the lobby. Then, after the movie, we turned off the lights, explored the theatre and took pictures.”

The swim itself is about a mile and a half. It’s an organized swim with spotter boats and emergency personnel to help swimmers who get in trouble. More than 100 swimmers are expected to give it a try on Sunday.

Waterbury thinks it will take him longer to make the distance than it will his daughter. Balant plans to make the distance in about 45 minutes to an hour. Both of them plan to wear wet suits.

Balant swam the 200 meter individual medley and the 100 meter butterfly in high school. Her method is to do eight to 10 stokes underwater with her eyes closed and then look up and forward to see if she’s headed in the right direction.

Swimming the outlines of nearby lakes helped them to get used to different wakes and motion in the water. And neither of them are worried about sharks.

“There are sharks in San Francisco Bay, but they mostly stay on the other side of the Golden Gate Bridge,” said Waterbury, who is an events planner for the Kitsap County Parks Department. “To be honest, I’m more worried about how cold the water is and getting hypothermia.”

In fact, if a swimmer isn’t done within two hours, they are expected to go to shore in a spotter boat. The currents where they will be swimming are strong and choppy because they are coming across from Japan, hitting the California Coast, Waterbury said.

“There’s only so much time you can be in water like that,” he said.

This may be the last dad-daughter event for awhile. The day following the swim, Balant and her husband, Brit, will pack up for their move to Germany. She works for the Department of Defense and is being transferred to Wiesbaden.

Her mother, Debbie, won’t make the trip to San Francisco to watch the birthday swim, but will be cheering them on from home.

As for Waterbury’s next challenge, he’s hoping to dunk a basketball.

“I use to be able to do it,” he said. “I’m working on exercises to build the muscles in my legs. But it  might be a pipe dream now, though. I’ve had five knee surgeries.”

As for his daughter, whatever her dad wants to try, she supports him.

“I’m just so proud of my dad,” she said. “He’s really been training for this. And I just love that he and I make it a point to do fun things together.”