At the end of a session when everyone is logging off, you likely have a good stock of cursed cannonballs left over, with no way to sell them.
If there's another ship in sight I'll sail over and give them to them before I leave, but if I can't see anyone on the horizon that's not an option.
I usually sail to an outpost, and fill a barrel in the tavern with all the cursed cannonballs we have, so if someone checks there, they'll hit the mother lode.
Means there's at least a chance they aren't lost when we log off and might be able to help someone out!