I was out in the sun for years. Before we knew about skin cancer. Light complexioned with deep tan from being on the water all day every day. Had more than one girl amazed at how dark I was with blond hair. Now I don't worry about tan lines, just the scars from skin cancer being cut out.
If you want tan lines buy a cheap bra and panty and get a spray tan. Most of the women I know work at not having tan lines.