Most families choose to release all of the cremated remains at sea. Some do not, and that is a completely legitimate choice with practical options that families should know about.
There is no legal requirement that all cremated remains be disposed of at once or in the same manner. A family may release a portion at sea and retain a portion for other purposes — keeping it in an urn at home, burying it in a plot, placing it in a scatter garden, or distributing it among family members. The disposition permit covers the at-sea portion; the retained portion requires no additional documentation for private storage.
A growing number of families use keepsake urns — small containers designed to hold a token portion of ashes for a specific person to keep close. These range from simple pendants and rings to small decorative urns designed for display. They are available from funeral homes and directly from artisans who specialize in memorial objects. Some families purchase one for each adult child; others reserve a single keepsake for the spouse or partner.
Some families who have scattered ashes at sea subsequently choose to have a portion of remaining ashes incorporated into a memorial reef structure — a concrete formation designed to support marine life, placed on the ocean floor. Several organizations offer this service on the West Coast. It is an option worth knowing about for families who want a physical memorial location in the water as well as GPS coordinates from the ceremony.
The question of what to do with a person's remains after death carries weight that rules and options do not resolve. What matters is that the family makes the choice that serves the people who loved them. Releasing all the ashes at sea is complete in itself. Keeping a portion is also complete in itself. Both are whole.