“I feel that when I jump off a cliff, I'm obeying (the) laws of the universe.”

Cosmic or crazy, the words come from a man named Carl Boenish, the subject of a new documentary called “Sunshine Superman.” Boenish (rhymes with “danish”) is the founding pioneer of the sport of BASE jumping, one of the original adrenaline junkies. Tom Cruise probably wouldn’t be Tom Cruise without him.

But Boenish is light years from a Hollywood headliner. That may be one of the most compelling parts of this life story. Boenish looks more like one of the guys who founded Microsoft than someone ready for the X-Games. His wife, Jean, looks more like a librarian than someone who would jump off El Capitan.

“Sunshine Superman” is one of those documentaries that can afford to go through the motions because it's fortunate enough to have a fascinating subject. Director Marah Strauch moves through Boenish’s story chronologically, focusing in on the late 1970s and early '80s for the heart of its action, and underscoring the material with classic rock tunes from The Byrds, The Hollies and many others.

After starting out as an engineer, Boenish became addicted to skydiving and eventually steered into a career as an adventure filmmaker. But by the late ‘70s, he was looking for new challenges. Apparently, 1,500 parachute jumps in 15 years leaves the thrill-seeking soul a bit restless.

The answer came in the form of what eventually was dubbed BASE jumping (Bridge, Antenna, Span and Earth). And because Boenish was such an avid filmmaker, “Sunshine Superman” benefits from a wealth of up-close-and-personal footage.

Early in the film, Boenish and a few like-minded associates decide to jump off the edge of El Capitan, a 3,000-foot cliff in Yosemite National Park. The jump itself is stunning, but footage of Boenish perched on a 20-foot ladder that extends off the edge so he can get a better filming angle of the jump is staggering.

It’s moments like these that underscore a theme in “Sunshine Superman” that is skimmed but not explored: Isn’t BASE jumping kind of … illegal? Maybe even stupid?

Not according to Boenish and crew. Old recordings of the adventurer show a relentless spirit that behaves as if his passion is his destiny. A Christian Scientist, Boenish goes as far as to suggest that jumping off cliffs is his way of demonstrating his right of dominion over the earth.

All the footage of the jumping — which later includes skyscraper jumps in Houston and Los Angeles, among other locations — is spectacular, if limited by near 40-year-old technology. You have to wonder what the man would have done with a GoPro.

But one of “Sunshine Superman’s” more compelling subplots is its love story. Jean Boenish was anything but a fretting wife waiting behind while her husband toyed with oblivion. She was right there jumping off cliffs with him. It’s a tender subplot, made even more so when you realize why Carl Boenish doesn’t turn up in any of the current interviews.

In the end, “Sunshine Superman” does a solid job of characterizing its subject, but it stops short of exploring the deep moral considerations of its theme. At numerous points the legality of BASE jumping is referenced, but you get the feeling that “Sunshine Superman” is content to sit at the edge of the moral cliff instead of follow its subject on a serious dive of discovery.

It’s a routine documentary about a fascinating man, albeit one with a great classic rock soundtrack.

“Sunshine Superman” is rated PG for frightening action footage, some profanity and a couple of extremely brief flashes of nudity in some photo stills.

Joshua Terry is a freelance writer and photojournalist who appears weekly on "The KJZZ Movie Show" and also teaches English composition for Salt Lake Community College. Find him online at facebook.com/joshterryreviews.