In case you haven't seen these already, this is basis for the Blitzkrieg variant.

from http://www.dipwiki.com/?title=Blitzkrieg

Blitzkrieg aka 1939.Blitzkrieg. created 2002 in France
Author: Stefan Mrdja (text revised by Craig Connell)
In Standard Diplomacy seven nations are standing on the edge of
World War I. Taking place several years later, this 8-player, 53 Supply
Center 1939.Blitzkrieg variant takes us to the beginning of the second
global conflict. 27 Supply Centers are required to win this game.
Rules

1939 Blitzkrieg is played according to standard rules. In addition to
the usual players, Spain is included in this variant; with Turkey and
the Balkans playing a more active role. England starts play at two
locations: the British Isles and North Africa / Egypt with a total of 5
Supply Centers.
There are special features on the map, which is similar to the Modern Variant.
Among the new items is the inclusion of Supply Centers in North Africa,
two additional ones in Eastern Europe, the division of the Black Sea
into two parts, and additional Supply Centers in Ireland, Sardinia and
Sicily.
Coasts: Leningrad is divided into North and South Coast. The only
opening play possible from the Fleet in (LEN) is to (LAP) or (BAR). The
province Rome is divided into an East and West coast. Any unit in
Sevastopol cannot move from (SEV) to (CAU) directly - or vice versa.
Passages / land bridges: There are three land bridges on the map:
between Clyde (CLY) in Scotland and North Ireland (NIR); between Tanger
(TAN) in Morocco and Granada (GRA) in Spain; and between Naples (NAP)
to Sicily (SCI) in Italy. Armies do not need to use Convoy orders, but
can directly use these passages. For example, A Fleet in Naples (NAP)
can not directly move to Sicily (SCI) or vice versa. Only armies can use
these land bridges.
The Sudan/Red Sea: A fleet in Alexandria cannot move into the Sudan (SUD), as the Red Sea is not passable.
Switzerland and Sweden are neutral provinces and thus are not passable.
The following islands are shown on the map, but are not passable: Corsica, Balearen, Cyprus, Crete
Unclaimed Provinces:

At the start of the game, these provinces contain unclaimed Supply
Centers:
Caucasus, Mauritania, Norway, Lithuania, Dublin, Denmark, French West
Africa, Lisabon, Tripolitania, Damascus, Greece, Sicily, Venice,
Bulgaria, Rumania, Piedmont, Hungary, Austria, Warsaw, Danzig, Holland,
Belgium, Sardinia.