The Hideous Mountain

From the introduction: This adventure can be run as a level 6 adventure for 5 players, or can be easily customized to a party of any size or level. It can work as a small side adventure in an existing campaign, as a standalone one-shot, or the start of a new adventure. Use the links to the tools in their relevant section to customize the adventure to your party. Play out the initial chartering of the boat as you like. This module can fit into an existing campaign when the players need to sail somewhere, or as a one-shot that starts at sea.