Writer's Digest Prompt Senario

The ocean is a vast and beautiful thing. Taking a quick peak off the side of your boat you realize something strange. The tentacles slowly creeping up the hull aren’t your imagination and the captain’s nowhere to be found. Where do we go from here?

     Adjusting his sailor hat, the young man breathed in salt water, now spraying his face.  He followed the ship's trail to the horizon. Flying fish caught his attention.  Oh, he loved being on the ocean, drinking in the vastness of it all.
     Suddenly he fell against the bulkhead. The trail disappeared. The water became still. He heard the engines screech like a trapped animal.  Sam pulled himself up and felt the back of his head. He looked at his hand - blood. Wiping his hand on his pants he walked over to the back of the ship.
     Strange black tentacles reached from the ocean deep, slow and in charge. The captain was not in his usual spot. One more glance he found that everyone was gone.
     A harpoon, get a harpoon, he told himself. Turning around he ran to the steps. Without touching one step he slid down on the handrails. Quickly looking around he found the weapon in the corner. Rushing up the stairs he found the creature had blocked his way.
     He aimed the weapon at the monster. The ship shifted and his harpoon went off sending the arrow into the side of the ship.  The tentacles continued to descend, causing the sailor downward.  The ship took another roll. Then another roll.
     "Wake up," a ship mate shook Sam.  "It's your watch."