The original reason for the departure was a certain feature just to the north of Hobart airport called Mt Lord. A departure from 30 takes you to the west of this feature.
In the early days of turbine and jet operations into Hobart this mountain could get in the way of an aircraft having to do a right hand circuit to return for a landing following an engine failure. The departure was designed to get an aircraft to the east of the mountain where there were no such obstructions to impede an aircraft.
From memory and being too lazy to go and get my Jepps, the turn was not before 500' or the departure end of the runway. Some turboprops still use the departure but the present day pussies in jets don't appreciate the fun.
With weather better than 1000'/5km its do-able but not that appropriate for jet ops.
The last jet that I have seen doing the departure was the freight 727 that used to be based here. Ansett and TAA used to do it as a matter of course in their jets. Real pilots.
