You can take my game… when you pry my cold, dead fingers off the board!
pg 8 of rules under Blitz:
"You may also move any number of your tanks and planes from up to three regions away into the region you're blitzing. Regions moved through must be connected by a land border or a sea zone with an anchor symbol (which you must have permission to cross). ...You cannot disembark during a blitz, or cross a sea zone without an anchor. Sea Zones do not count as regions when counting spaces.
Planes can fly over a hostile region and into another region, but tanks must have an uninterrupted path of friendly regions or sea zones with anchor symbols, or they cannot join the blitz."
So yes, but only Anchored Sea Zones (ASZs).
Confusingly, the second paragraph leaves out mention of ASZs for planes, or "crossing with permission" for tanks but taking into account the first paragraph, I believe they can. So...
- Tanks may cross ASZs, whether friendly, empty or with permission if hostile.
- Planes may cross ASZs even without permission, and fly over hostile/neutral regions.