I just explained the extra scene to newexistence in the comment above. Going to copy it and paste it here ;-).

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The last scene, after the credits, shows Elizabeth and her 10 years old son in a cliff and they were watching the horizon for Will to come back. And then there was a flash of a green light and up from the sea came the Flying Dutchmen ship and Will looked over and smiled. I guess because Elizabeth remained faithful, the curse was lifted and Will could be alive again to be with Elizabeth and their son.

It was a beautiful scene.

:)))))))))))))