This Achievement can be obtained in the Geothermal Valley next to the Ridgeline Base Camp which can be accessed either before or after exiting the Archives mission.
To the right of the Camp then is a ramp that will be used to perform the swan dive. Back away from the ramp and click
in to sprint towards the ramp, as soon as you hit the edge hit
and then quickly tap
to perform the correct dive.
This might take a few attempts because of timing but if you fail simply reload back to the Camp and try again.