We've always warned the ocean is a cruel mistress, but do people listen? A middle-aged Florida couple recently found out the hard way the unforgiving nature of the briny deep.

The pair unwisely went scuba diving in the Gulf of Mexico without a pal to mind the boat and emerged from the underwater exploration to find the tide had carried them out of reach of their vessel.

Following that was a grim, 24-hour odyssey of shark fears, hypothermia, hallucinations and agonizing near misses with potential rescue craft.

The hapless divers were finally saved around noon on their second day of bobbing around when they spotted a boat manned by two teenage boys in the distance. They used their last reserves of strength to swim across the open water and were hauled aboard by the young brothers.

Keep this story in reserve for the next time your girlfriend tells you she wants to spend more time together.