Dragon Turtle's Shipwreck

From publisher blurb: Dragon Turtle’s Shipwreck is a Fifth Edition plug-in adventure for four characters with an average party level (APL) of 11, 14, 17, or 20. This document offers details for each level and makes adjustments accordingly. The adventurers must travel deep below the ocean’s surface to the remains of a wrecked pirate ship. Within, they will find innumerable treasures. Unfortunately, this treasure is part of a hostile dragon turtle’s hoard.