The ancestors of the people in Pacifidlog Town were said to have been born on boats then lived and died aboard them. According to legend, they lived that way because they were searching for something.
So what exactly were they searching for? Though small, their town is in close proximity to two major landmarks, atleast in terms of Legendary Pokemon: The Sky Pillar and Sealed Chamber.
However, if they were searching for Rayquaza, it is safe to assume that they are Dragon Tamers, but nothing about them seems to suggest that. It also seems unlikely that they wouldn't have noticed the Sky Pillar either. Perhaps they were looking for the Sea Floor cave in search of the big fish, Kyogre, after all what greater honour would it be for a fisherman than to tame the greatest fish of the sea....
However there is also the young lady who says her grandfather used to say "Six dots open three doors"
Now this is a stretch, but perhaps they were searching for a special Regigigas, the very same one that would allow you to unlock the Regi events in platinum. Yeah the six dots could refer to braille, but Regigias himself has six dots for eyes (like other regis) and does open the Regi event in platinum.