Anchors can symbolize different things depending on context; the anchor can be a simple allusion to nautical life, but it can also have a religious meaning, particularly for Christians. In this more religious context, anchors can represent feelings of hope, which is referred to in the Bible as the "anchor of the soul."
Because the anchor is used to secure a ship and keep it from moving out of a designated space, this piece of equipment is also commonly associated with safety. This sense of safety relates to the feeling of hope reflected in the Christian symbolic ideology. Additionally, the use of the anchor as a stand-in for a cross dates back to a time when Christians were persecuted.