Any hints on how to make a map where ships are not playing the second fiddle, while maintaining a possibility to win a game?
SirVer already answered the question basically. However as I wrote in my previous post: there is no restriction on the type of map. Of course it would be preferable to create a 100% winable map - anyways, keep in mind that there are different win conditions like land lord.
So, yes it is not easy to create a seafaring map, where everything can be reached via land but ships still do not "play the second fiddle" - but if it was easy, there was no reason for a map contest
Just two ideas: If it is hard to get to some parts of the map because of land-bottle-necks, or if some specific things are missing on the starting positions and they are available far away from all the starting positions, but can be reached by ship quite fast... in that case things might already look different
And again.. it's as well hard to create a map, where you can not reach ever piece of land via land but still the game is definitively winable for all players - one way is to create a special win-condition via scripting.
... and if the map is build up of islands and there are ways that nobody wins the game... well at least that's something that pushes us developers to implement the "clean space on opposing players island to build your own harbour" feature as soon as possible so we can include it in Build19/1.0