This is my story.

Tidus: Yuna, I have to go.
Yuna nods "no".
Tidus: I'm sorry I couldn't show you Zanarkand. Goodbye!
Tidus is about to jump off the airship.
Wakka: Hey!
Rikku: We're gonna see you again...?
Yuna runs after Tidus.
Kimahri: Yuna!
Yuna tried to hold on to Tidus, but she went through and fell down. Tidus is disappearing. Yuna gets up.
Yuna: I love you.
Tidus gave Yuna a hug although she can't feel him. Then Tidus is about to jump and the group started waving goodbye. Tidus jumps off the airship, and we see Jecht, Auron, and Braska. Jecht reunites with Tidus. Later in Luca, Yuna tried the whistle blow with fingers, but it is no use, as we know Tidus is gone.