Here's Several Tanks I've been working on for Mariner's Blight. All of them were OOP Space marine tanks that I upgraded with new Chaos tank parts and Baneblade engine exhausts.
I added lots of valve seals and airlocks for that submarine look as well as Harpoon Launchers on the Rhinos. Extra armor plating, tow hooks and ladders completed the look. The Dozerblades on the Vindicator are from Kromlech.