We played a 6-player game of Small World with the Necromancer Island expansion and a lot of fun it was too. Our Necromancer pulled off a narrow win by getting his 14th ghost onto the map at the very end of the final turn, it doesn't get much more climactic than that!
Part of the Necromancer's success of course was getting himself into a position where it was nearly impossible for the other players to effectively oust him from the map; and in part he achieved this by investing in Seafaring, and taking both one of the map-edge sea regions... and also the lake surrounding Necromancer Island.
The thing is, the rules are slightly unclear about how Seafaring interacts with the Necromancer Island expansion. Necromancer Island itself does not count as a normal board region, and the rules explicitly state that the island's "Lake Region is immune to other players (even Seafaring ones)".
So does that mean that, with the Necromancer's Island expansion in play, the central Lake region is completely out of bounds to Seafaring races? Or out of bounds to other Seafaring races, but available for conquest by a Seafaring Necromancer? Or that the Lake region can be conquered by Seafaring as usual, but the island is unconquerable (and can still attack territories bordering the lake even if the lake is occupied)?
I ruled on the night that the Necromancer could conquer his own Lake... if only because the Seafaring power seems pathetically bad in a Necromancer Island game otherwise! But it's not at all clear to me that it's the right answer. If anyone knows of, or can hazard a guess at, an official ruling, it would be much appreciated!