Ore patches now spill over into the sea as submerged variants. Dredge them up with new floating hardware, and build deeper into the blue with water-placeable refined concrete.
Currently the default upgrade planner cannot upgrade the floating transport belt. I would expect the yellow floating belt to be upgradable to the red floating belt and so on.
Unfortunately, this appears to cause issues with modded belts that set themselves as upgrades to the vanilla ones, such as Krastorio 2's advanced transport belt. If I turn on limit floating belt generation, the game won't load. "Error in assignID: entity with name 'floating-kr-advanced-transport-belt' does not exist."
And there's the something weird going on. I'll take a look at this when I find time - guessing it's not that hard to address, and if it isn't it should be fixed in the next update.