The POB is actually noted on the "Supplementary Flight Plan"...that's the bit at the bottom of the form with Endurance, Emegeny, equip, etc. Not "normally" tx'd, but can be dragged out from the ATSU from whence it came. if they bothered to fill that bit in, of course. Some do, some don't, even in a single going over water
watp,iktch