During the industrial revolution a lot of the big mills and factories had fixed shutdown times during the year and all the workers would holiday at the same time, usually travelling to the big seaside resorts mentioned here. These were their boom days and really ever since has been a gradual decline as that way of live and it’s cultural imprint has washed way down the generations. See Also: EasyJet.
As a Brit living in Japan, I'm struck that the connection between organised crime and seaside towns seems, unsurprisingly really, to be a universal phenomenom.
For example, in Japan the seaside town of Atami in Shizuoka is where the Inagawa-kai (3rd largest yakuza group) was founded in 1949. [1]
Edgar Wright's new film "Baby Driver" makes virtuosic use of Queen's "Brighton Rock" in it's grand finale. Don't think I've ever witnessed that level of per-frame synchrony with every beat!
This phenomena applies to a number of beach towns, especially Santa Cruz which does its best to take California informality well past eccentricity. It's awesome and definitely a defining aspect of Santa Cruz culture.