Because no summer movie season now seems complete without one, Adrift is this year’s model of sleeper with a starlet (here, Shailene Woodley) struggling to survive on the seas (here, a sailboat ripped to shreds in a hurricane). Thanks to Woodley and co-star Sam Claflin’s convincing chemistry, Adrift is certainly a more emotionally engaging bit of misery business next to the cheeky exploitation of 47 Meters Down or The Shallows. But its bombast feels like ballast next to its buoyant romance and its dovetailing chronology increasingly intrudes on any momentum the performers build.

Woodley embodies the real-life role of Tami Oldham, a rudderless twentysomething for whom a Tahitian boat-scrubbing job circa 1983 is just the latest port of call away from her broken family. It’s there that she meets Richard Sharp (Sam Claflin), a sensitive sailor roughly 10 years her senior living off big paydays by sailing wealthy folks’ vessels beyond the sea on their behalf.

Tami and Richard roll with roustabout lives, ever willing to wing it on the wind. Together, each comes to feel like the other’s unanticipated focal point on a horizon they’d never considered. In Richard, Tami recognizes that wanderlust and wellbeing are not mutually exclusive. In Tami, Richard sees a fellow traveler who, even paired off, will chart her own course. Claflin and Woodley create a convincingly charged connection in the moments of Adrift conveying their courtship.

Claflin’s got the chiseled Cavill Jr. thing down pat but also lets Richard’s affection for Tami reveal itself gradually, and in a way that seems to surprise the character. Few actresses so effortlessly convey unexpected charm, or conflict, quite like Woodley. There is sincerity and surprise in her raspy laugh over the chemistry she’s conjuring, and it’s every bit as precise as her subtle shift and slouch as Richard gets a $10,000 offer to sail a luxury sailboat to San Diego … the home from which she’s hiding. Moreover, Tami doesn’t want to feel like she’s merely following Richard on his adventure. There would, of course, be no true story on which to base the movie if Tami hadn’t changed her mind. However, it’s less out of convenience than it is a believably romantic, in-love persuasion from Richard.

Soon enough, though, they’re inadvertently sailing right into the center of a hurricane. Tami is thrown topsy-turvy in the boat’s hold while Richard is flung from it. After gathering her bearings, Tami spots Richard clinging to detritus and brings him aboard. With shattered ribs and legs, he’s no help beyond inspiration to persevere. And so they take a risk that adds hundreds of miles to their journey — but puts the current at their back — to hit Hawaii or die trying.

Adrift intercuts these storylines from start to finish, ostensibly for a simultaneous peak and a way to save those rogue-wave visual effects for a slam-bang finale. Although an admirable attempt to distinguish the disaster narrative from linear expectations, it ultimately enervates the urgency of Tami and Richard’s predicament, the undulations of their romance and the goodwill generated by its leads.

For all that meteorological dun-dun-dun in the final reel, no effect is as thrilling as an early date in which the camera eventually follows Richard off a cliff — worried the headstrong Tami has gotten in way over her head. Ultimately, too much of the film feels like director Baltasar Kormákur retreating to the rhythms of his last film, Everest, with less persuasive depictions of physical maladies to keep younger audiences from being grossed out. That PG-13 rating is mainly thanks to unexpected nudity and not the profanity with which anyone would face this situation.

Although the bodies still look good even after all that sun, our heroes succumb to a certain type of deterioration — one akin to another such soggy summer sleeper, at almost the exact same moment, and leading to an obnoxiously tight hand-hold in the climax. Whether you find these moments overwhelmingly emotional or hilariously hoary, your eyes will flutter in some sort of movement as your heart might at its outset.