This one's a light fantasy, perhaps inspired by Jimmy Buffett. Fins Up!
It's prompted by:
Joshua leaned hard against the tiller, fighting exhaustion.
“That’s gotta be it,” Kelly called from the front of the sailboat. “It looks like a giant shark’s fin.”
Joshua remained silent. The sea was glass. A meager breeze to fill the jib was all he could conjure after three days becalmed.
Kelly climbed over rigging and past the mast to where Joshua slumped against the gunwale. She pulled a flask from her sash and held it out to him.
“Drink this,” she said, but Joshua shook his head. “Don’t be daft. It ain’t rum. It’s the juice o’ the Mountain Beans. It’ll pick ya right up.”
“And then send me crashing into Morpheus’s clutches,” he said, but he snatched the flask from her anyway, gulped it down, and handed it back.
Kelly smiled and dribbled the last few drops onto her tongue. “But by then, we’ll have the treasure aboard.” She turned back to the island. “Now, let’s find that cave.”
Using the strength of the restorative, Joshua whipped up a stiff wind while Kelly raised the mainsail.
“There it is, the Shark’s Mouth,” Kelly shouted as a gaping opening in the cliff face came into view. Rows of stalactites hung from the roof of the cave like shark’s teeth, glistening red in the dying sun. She scrambled to light a lantern as they drifted into the tunnel on the last breath of Joshua’s breeze.
Kelly held the lantern high, looking for the reflected glint of gold.
“Drop the wind,” she said, a note of concern in her voice. The tiny boat picked up speed.
Recognizing their mistake, he muttered, “It’s not me.”
The sunset glow behind them blinked out as the descending teeth of Shark Island splintered the boat and sucked debris and sailors down its gullet.