For stories about the "Great One," they will vary! Some key points would be:

• Speculations that it is a leviathan because what else could have that kind of power?
  
  
• Most stories will be about its destructive power similar to what is already known—tales and legends of island lost to a tsunami after invoking the wrath of the "sea gods." The common cause is excessive harm and brutality to creatures and folk of the sea, including mermaids and sirens.
  
  
• However, there are other more positive tales, especially in peaceful coastal villages that often have good fishing. These places often revere some version of a "sea god" or "entity," though careful research would notice some similarities to them even if they go by different names or descriptions. Some will have tales of people lost at sea or believed to have drowned to have miraculously washed ashore, and such survivors will say they felt a "magnificent presence" when they were saved. Others will have historic tales of their island once saved from attackers by a giant rogue wave that destroyed entire ships in one blow.
  
  
• Asking seafolk such as the whales, mermaids, sirens, etc. will yield little to no results—except for the inkling that they may know something but are refusing to say anything. All they may say is that some legends and myths are true, and that if they won't want to risk anything they should respect the ocean and all who live in it.

As for Faulkner sharing his own stories, there would likely be varying reactions! Some may find it interesting, others might not care, find it strange, or have opinions depending on what Faulkner shares.