In 1960, surfing became massive all over the world not only as a competitive sport but as a cool hobby. The whole style of the beach look took the world by storm and suddenly it is not just surfers wearing board shorts and flip-flops but people who want to look like they've just come off the beach wearing them as well.
From shorts to board shorts:
The original mens board shorts style derived from ancient forms of swimming trunks. Similar to what they are today they are long, but they have a lace-up front, thick seams, and buttons are inconveniently placed when paddling on the surfboard.
They did not quickly drain from the water, which means when they are difficult to wear while surfing, horseback riding, etc. They are comfortable and practical.
Short evolution first board:
It was only until 1970 that two Australian surfers designed board short and changed the mode forever. They designed a short deliberately to surf, everything about it, from the materials, used, the waistband, length, where the keys are placed, whether to use layer and so on.
They are designed specifically for surfers to brief their surfboards, hence the name 'board pants'. Every surfer who wears them says they are the most comfortable shorts for surfing they never used, and by word of mouth style and brand name to grow and grow to the phenomenon that it is today.