The anchor is a life saver - it can prevent a ship from crashing on to rocks. For Christians, the analogy is that Christ can save spiritual lives. The nautical image of an anchor gives the idea of navigation (through life).
The Anchor Cross can take various forms and just a couple are reproduced here: The 'traditional' shape shown on the left, or comprising three crosses as shown on the right, where it represents the three crosses on Calvary, or the Holy Trinity.
The word 'anchor' in Greek is ankura, and a pun is the Greek phrase en kurio, meaning 'in the Lord'.
The anchor is a life saver - it can prevent a ship from crashing on to rocks. For Christians, the analogy is that Christ can save spiritual lives. The nautical image of an anchor gives the idea of navigation (through life). Alternative names include St. Clement's Cross, Sailor's or Mariner's Cross.
Another cross that helped early navigators was the cross staff, an instrument for measuring latitude. The staff was marked with a scale and fitted with a sliding cross-piece set at right-angles to the staff. With the tip at the navigator's eye, the cross-piece was slid up or down until its upper edge aligned up with the sun or polar star and the lower edge with the horizon. The reading on the staff was converted into degrees by referring to a table.
All much simpler to operate than today's GPS.
However, we landlubbers forget the obvious point that the anchor has nothing to do with navigation. On the contrary, the anchor stops you from going anywhere.
It certainly stopped Clement, the fourth Pope, in the 1st century. Emperor Trajan banished him from Rome and forced him to work in the harsh Russian stone quarries. Clement caused trouble for himself by locating a spring of fresh water that could quench the prisoners' thirst. Whether or not the appearance of this spring was a miracle, we don't know for sure. But he was eventually made a saint so it's possible the church authorities later believed it was so. In any case, the prison governor of the time was sufficiently peeved to order Clement's death. He was executed by being tossed into the Black Sea, tied to a heavy anchor to prevent other Christians from recovering the body. The cross is therefore sometimes called St. Clement's Cross and Clement became the patron saint of anchorsmiths, blacksmiths, mariners, marble workers and stone cutters.
Clement was considered a renegade and ever since, the Anchor Cross has been used by Christians who do not wish to conform to the state religion. When Christians have been persecuted and forced underground, their emblem has often been the Anchor Cross. To the outside world, it was just an anchor. To the Christians, it was a camouflaged Latin Cross. Like a ship's anchor, it helped them to keep their faith firm in the stormy social and religious environment. They took comfort from the Epistle to the Hebrews 6: 19, which says: "We have this hope, a sure and steadfast anchor of the soul, a hope that enters the inner shrine behind the curtain."
This cross is also attributed to St. Nicholas of Myra, being the patron saint of seamen.
See also St. Nicholas Cross and Avellan Cross.