re: #679 ObserverArt
It is also considered the “Surfers Cross” from as far back as the 60s.
Here is a Google image link with Surfer’s Crosses.
I used to have one on a chain as a necklace back in grade school…like ‘64 or so.
They were big with Hell’s Angels as well…I recall having one as a kid because I thought it was bitchin’ cool.