[Guest]

are the English Channel maps 1:1 ?

No; I think they are roughly 2:3.

If you are interested though, a 1:1 scale channel map is being developed by the 352nd group here: http://352ndfg.com/smf/index.php?board=33.0

Please note the channel map included in HSFX is not to be confused with this one nor compared. Both serve (or in the case of the 352nd one will serve) different puposes and are incomparable IMHO