They are naval tattoos. The navy is what brought tattooing to the Americas. They are considered a big part of tattooing history. Both of my grandfathers served in the navy. When they passed away I got an anchor for each of them on my hands. This symbolizes the term anchors away or to throw anchors. It means you're ready to fight. That's why popeye had one anchor on each arm. They are a huge part of traditional tattooing and have become a beloved part of the contemporary tattooing community.
Mainly because of the history of tattoos , many sailors had them, so an anchor is a good one, if you are or served as a sailor, I have an anchor one with a scroll on it, with dad written in it, he served as a sailor in Korea.