There are some VERY important sea regions. For example, if France sneaks into the English Channel in 1901 it can be devastating for England's long term strategy.

I would say the north sea is far more important than the channel. The ionian as well.

You might go to the archives in the resource section of the Diplomatic Pouch
www.diplom.org

There may be a few articles on the Black Sea and the Channel, but a specific article on a sea strategy does not leap to mind.

General country articles talk about the value of various spaces including the seas.

It is difficult to isolate the discussion on sea spaces without understanding what the diplomacy and structure of strategy is. You can talk about the value of some techniques such as the convoy, the support of a convoy,
the switching of places, and counting of options for each sea province.

The question is what are trying to get at? A national policy sort of approach such as how does England and Germany work a Fleet-Army alliance structure or what?

could you tell me what articles other players pointed you twords?

towards

I've learned one thing: If you're Germany and you build a fleet, England will attack. Other countries, not so much.

Perhaps deriving from my coastal roots, I have a particularly fondness for fleet building.... ruling the waves can be extremely powerful, especially when other nations focus on armies. Even as Austria I once managed to build 6 fleets and took Liverpool to secure the win.

In addition to the obvious key spaces of Black Sea, Channel, North Sea, i'd add the Baltic. Very powerful for a Russian fleet trying to get at Germany (something to think about if you think he will bounce you out of Sweden in 1901). As the game moves towards the mid/end game I believe that in the majority of cases, the MAO/Ionian become the most important squares on the board given their ability to bottleneck superior forces from Turkey/England and prevent them crossing the all important stalemate line. As a general rule I believe a lot of players on this site undervalue the instrinsic value of these squares.

The Influence of Sea Power in Diplomacy might help too:
http://www.diplomacy-archive.com/resources/strategy/articles/sea_power.htm

1) Thanks everybody for your contributions

2) Thank you especially to Braveheart: the article was just what I was looking for, but I could not find it (stupidly I titled this post "sea strategy" but I googled for "naval strategy" and "use of fleets" instead).

2) For Carpysmind: http://phpdiplomacy.net/index.php?viewthread=312392#312392