It is easy to understand why. The required monthly physical training test includes wide-arm push-ups, situps, pull-ups, chin-ups, 12-minute crawl swim (500-yard minimum), 25-yard underwater swim and a 200-yard buddy tow.
On Mondays, Wednesdays and Fridays, Kessell's workouts includes push-ups, situps, resistance training and up to a five-mile run. During lunch he rides his bike.
Twice each week he spends two hours in the water, conditioning his body with timed laps back and forth, up and down the Olympic-size pool.
On a recent day he lead two other recent graduates in a series of anaerobic exercises. Kessell used his stopwatch to time the trio as they raced the length of the pool, 25 yards in 30 seconds, pausing for 10 seconds, then taking off again.
"We are all about operating at our physical best," Wentz explained. "We sell lifestyle and fitness here for a lifetime, for a career. That's the only way to keep our people productive."
Petty Officer 3rd Class Michael Baierski, 23, a recent graduate, said becoming a rescue swimmer was the hardest thing he'd ever done.
"If you don't have your mind 100 percent, you're not going to make it. And if you're not giving 100 percent every single day and pushing yourself as hard as you can, you're going to get kicked out of school," he said.
Baierski said that graduating from the rescue swimmer school means that he has accomplished something that most people can't, which is what Matt Novellino, 27, of Denville, N.J., is trying to prove. This is his second opportunity, and already his class of 12 is down to four.
Over the past six weeks, he, Josh Mros, 23, of Charleston, S.C., Josh Mayfield, 21, of Chesapeake, Va., and Ben Cournia, 25, of Bemidji, Minn., have become close friends.
Novellino was a member of the disbanded class, and he got to attend the following course instead.
Discussing the different challenges of the course, he said the school's instructors "push right in the beginning to see who's going to quit."
"That way they know who is dedicated. They don't want to be wasting their time," he added.
For Cournia, it's the physical challenge. Though he is the best swimmer of the group, he doesn't have the upper body strength his comrades have. And despite two hours of physical training each morning, doing push-ups gets him down.
He said, however, that his comrades motivate him, along with the idea that if he gives everything he has, he won't be dropped.
"I know I have the ability to do this," he said. "And I want to be rescue swimmer."
As Coasties, they all must be good swimmers, yet each admitted the swimming part of the course challenges them the most. "They'll take you to your limits," Mayfield said, "but you have to go past your limits. They want to see if you can keep going."
Bemidji said the tough treatment candidates receive from their instructors comes from a desire to get the most out of them. "They are not mean, evil people," he said. "They get your blood up, but that's what they want to do. You can tell that they really care about how we're doing."
How well they are doing will be decided over the next 13 weeks. The four remaining students still have a long way to go, but Wentz said the four thus far are doing well.
Upon graduation, Novellino said he will take pride in knowing he has proved what he is made of, and that he achieved something his father, a Vietnam veteran, could be proud of. "That something to live up to," he said. "And I know he'll be proud of me."
Mayfield said his graduation moment will probably get a little emotional. "It's going to be a blessing," he said. "Because we will have the best job in the whole world."