On March 27, 1858, France passed the Breton Stripe Shirt Act, which made blue and white striped knitted shirts part of the French sailor's uniform.
It is believed that striped t-shirts help to find sailors who fall off the boat. Later, the striped t-shirt became the standard not only for the French Navy and fishing fleet but also for other navies around the world.
It became fashionable a century later. The classic Breton blue and white stripes are the symbols of the sailor, and the collar is also a prominent symbol of the French sailor's shirt. The collar's wonderful use is that it can quickly take off clothes after falling into the water, and won't jam the neck.