I don't understand why it would be unrealistic to travel. They are (were?) a company, they took jobs wherever they wanted.
If it seemed unrealistic HOW they traveled, I can agree with that... too often we have not put attention at the time spent to travel to one part to the other of the globe (the intrduction of the UFO engine on the Stormloader was my attempt to explain the short time they needed to travel to one point to the other of the globe).

The only way I see the Vanguardian limited to the island is if we resume the old plot of them being on the run from all the powers of the world, like when they were in the Circus.

I must admit that it's not a concept that scare me... in fact, it would work perfectly with what I set up in the Christmas issue, when Merlin managed the world to believe Vanguard is the same of the MBL.

I would like to to a run of stories that has to be set exclusively on the island... let's say three or four stories, or a year... but at some point the name of Vanguard has to be cleared and they should be allowed to travel freely again (or for the first time, in effect).

Bear in mind, Mxy, that while you and most of the others have Vanguard Europe as a place to write different stories, I have just Vanguard International, so I would like to be able to explore the HR Universe and not to be limited to La Perdita FOREVER.