There were two boat days in old Hawaii. The first was the arrival of the passenge liners, bringing family and friends from the mainland. 
 
The second was when the great liners broke the strings of flower leis that bound them to the shore and sailed out to sea. 

Passing Diamond Head, you threw your leis into the water. If they floated back toward shore, you would return. If they floated out to sea, you would never see the islands again.