From a 1995 patent for an "Interment vessel with directional capability":
There is a need for an interment device, at least for the benefit of the survivors, which retains the emotional benefits of dispersing the decedent's remains, e.g., sending the deceased to visit exotic far away places, or to occupy a favorite body of water after death, but wherein the survivors have a tangible item initially, as well as some expectation that after the deceased is dispatched this tangible item eventually will return the deceased to his loved ones for enshrinement. This need is satisfied by the device of the invention.
The interment vessel has or defines an openable watertight ash containment urn. The vessel has a main body with one or more protrusions defining at least one sail, and a keel. The sail intersects at a right angle with the upper surface of the main body and is inclined relative to the keel so as to sail at a reach. When released in the water the vessel sails in the prevailing wind and current, to an eventual destination. The vessel can include instructions to the finder of the vessel and can provide for a reward in exchange for, or in anticipation of, return of the remains to the loved ones who dispatched them.