Sanctuary – “Crimson Tide” [Campaign 4 – Mission 3]

Hello everyone! I also can't complete the map. I've defeated everyone and rebuilt everything. I have over 5000 creatures in my army, all of them swamp creatures. As I understand it, I need to cause a flood, but there isn't one. There are 6 ships, but I can't reach them (I'm running around them). Sometimes a ship with Necromancers appears. It says that not all Necromancers have been killed and that 2 out of 4 altars are under their control. Please write what else I can do. Thank you in advance!

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