timerover51
Deity
Darski posted this comment in another thread, but I have run into the same problem and developed a way of getting good archipelago maps. This works best on standard and larger maps, as I have not really tested it on tiny and small maps. It does require changing the game seed for world generation, and I admit that all of my tests have been done using the editor, not the initial world generation screen, but I assume that they would act the same way.
What I have discovered works best is to set the game seed to a 5 to 8 digit number, preferably NOT beginning with "1". I tend to use historical dates or dates that have meaning to me like: wife's birthday, anniversary, children's birthdays, family birthdays, holidays, dates of major battles (I am a military historian after all), and so forth.
Presently I am playing on a archipelago map based on 4 July 1826, the date of the deaths of both Thomas Jefferson and John Adams. It is 300 X 180, using Windows 7, and is a good archipelago map, with a large number of nice sized land masses. This is using the Conquest editor, but tests show that is also is pretty good for the Vanilla game and also Play the World. One of my better maps came from using my mother's birthday, appropriately named Della's World, and one using my first-born son's birthday, Brent's World. I have not used the day that he died however.
I do keep forgeting where I have preplaced opposing civilizations however, which is causing some problems. I tend to like developing for a while before running into the AI, hence the very large map.
