When I went to Jersey a few months back, my departure clearance back to London was " not above 1,200' on track MP ".
But this does beg the question if this is normal practice in the islands to fly out of gliding range?
Yes. That is pretty much the standard clearance you will get, and be expected to fly from Jersey to anywhere ... As soon as you clear Class D just before the French coast you can climb up higher ... or just demand a higher level like you did
ATC finally gave me the clearance to 5,000' initially, then up to FL100. They seemed a little flabbergasted by my lack of willingness to continue at a lower altitude.
If you were VFR then you could not be at FL100 anyway as class A starts at FL80
1. Why can’t I operate Special VFR above FL80 in Channel Island Airspace?
a. From 6th March 2014, Channel Island airspace went through a major re-classification process. The Channel Island Terminal Control Area (TMA) was established above FL80. This class A airspace precludes both VFR & Special VFR flight.