Instead of spawning in the zodiac, you'll spawn at the height of 800 feet with a glider right below you.. I couldn't make it so that you'd already be hanging in the glider, so you'll have to press the use key in the beginning. I also replaced the buggy with a humvee.

Download either xglider.pak OR xglider_nr.pak and models.pak. Xglider_nr.pak doesn't have the reflection patch, and the xglider.pak comes with the reflection patch. Place xglider.pak OR xglider_nr.pak into "Far Cry DemoLevelsFort" -folder AND models.pak into "Far Cry DemoFCData" -folder.

This mod doesn't work if u have installed the shark&jeepfix mod and/or water reflections mod, or any other mod that modifies the level structure (just delete them and it'll work).