At each of our reunions we conduct a "Two Bell" ceremony to honor those shipmates and their wives who passed away since the prior reunion.
Bells have a centuries-long tradition of varied use in navies and merchants fleets of the world. 
They have been used for signaling, keeping time and for providing alarm.  Their functional and ceremonial uses have made them a symbol of considerable significance to the United States Navy.
American ships, of the Revolutionary War and in our early years as a nation, adopted many of the practices and traditions of the British Navy, including teh use of bells.  In 1798, Paul Revere cast a bedl weighing 242 pounds for the frigate Constitution, also known today b y its nickname "Old Ironside"

In days past, two bells marked the end of the routine day aboard ship.  It also was time for tattoo (a signal on drum, bugle or trumpet for soldiers or sailors to return to their quarters) and soon, taps would sound throughout the ship. 
Various organizations perform the two bell ceremony slightly differently ours, and the following video fairly closely resembles the one used at our ceremony.
We open with the Navy hymn that was written in 1860 by William Whiting, an English writer and hymnist.  It was written as a poem for a student who was about to sail for America.  John Bacchus Dykes, an English clergyman and hymnist , set the poem to music in 1861.  The hymn became the Navy Hymn after it was played for devotional use and benedictions at the Naval Academy, in Annapolis, Maryland in 1879 by Lieutenant Commander Charles Jackson.