The zeppelin parts are all in the main fjords area, so you can fly around and check out wyvern nests as you explore various ledges, etc (there is also one on the small island near the grand knight teleporter shrine).
On this
fjords map the rough locations are marked with an
S. Alternately, from the D2:ED
walkthrough (the locations are the same in DKS),
-Crystal 1: on the tiny island just south of the entrance to the fjords; climb
up the ladder and retrieve it from on top of Yggdrasil
-Crystal 2: on a low cliff east of Camp Sentinel View, across the water from
Camp David
-Crystal 3: on a cliff in the middle of the bend just before the entrance to
Rivertown Gorge [EDIT on the same ledge as a boarded-up cave door]
-Rudder 1: a short ways east of the Camp Freedom teleporter
-Rudder 2: halfway between the Imps' Lair and Camp David
-Rudder 3: on a low southwest cliff near the exit to Rivertown Gorge
-Compass 1: on the cliff directly opposite Rudder 1
-Compass 2: high up above Moor's shack, just northeast of the entrance to
Keara's Flying Fortress
-Compass 3: on a cliff just before the bend on the way to Rivertown Gorge
For the flying fortresses, once you spend a little time running/flying around you should get the hang of them. You could take out the anti-dragon defenses in one area first, then go through in human form (or vise versa), to try to help keep track of where you have explored already. Some of the fortresses are easier to navigate than others.