Okay, So I’m going to opt for a combined approach for this. I’ll be using DistanceFields for all static mesh interaction with the water plane, and the landscape heightmap will handle interaction with the landscape.
I’m not sure of the limitations of the engine here (on materials and landscapes), but something I would absolutely love to see in future is Landscapes adding to distance fields (and/or) the ability to grab the landscape heightmap from within a material. I feel this would open up some really interesting interactions going forward.
Thanks again for the help! Once I get the DistanceField approach set up I should be able to post my workings here for you @Gmi