The Arch of Swords
Right after the ceremony, as the newly married couple exits the church, a group of fellow Navy officers line up in two facing rows outside the door. They draw their swords and raise them to form an arch or tunnel of crossed blades.
The couple walks through the arch. At the final pair of swords, the officers often lower the blades to briefly stop the couple so they can kiss. Then one officer gives the civilian spouse a light tap (hah!) on the backside with the flat of the sword and announces something like “Welcome to the Navy!” (or “Welcome aboard”).
This tradition, with roots in the Royal Navy, symbolizes the Navy family’s pledge of loyalty, protection, and welcome to the new couple. It is one of the most recognizable features of a U.S. Navy (and Marine Corps) officer’s wedding.
Commander (O-5), United States Navy.
The uniform is the U.S. Navy Full Dress White (or Service Dress White in a ceremonial context):
White combination cover with the standard Navy officer crest (eagle, shield, and anchors).
High-collar white tunic with hard shoulder boards.
Three ½-inch gold sleeve stripes (the hallmark of a Commander).
Naval Aviator wings on the left breast.–Grok