A sailpast is an event where boats with sails go past a certain point, often as a celebration or a show.
Sailpasts are usually happy events where people enjoy watching the boats.
Examples:
The sailpast was so pretty with all the colorful boats.
We watched the sailpast from the shore.
During the sailpast, the boats went by one by one.
The sailpast made everyone smile.
The sailpast had so many boats, it was like a parade on the water.
I saw a sailpast in a movie, and it looked amazing.