How to simulate fake terrain water in roblox?

I'm trying to create terrain water however the water doesn't make you float or sink and you can't actually swim in it. Basically, I'm trying to recreate the terrain water in the game "Booga Booga" where the "Terrain Water" just slows you're walkspeed down and nothing else.

I did try to make the HumanoidRootPart's density high enough but that don't do anything

1. In your tool bar go to "Home"

2. Click "Editor" in the "Terrain" section

3. In the "Terrain Editor" go to "Edit" section

4. Click on "Sea Level" and move it and adjust it however you like

5. Click "Create"

-- Test the water at the end, for me it works normally and it lets me swim in it etc.

That is easy, just create an invisible block then make it extra large

For the walkspeed do this

script.Parent.Touched:connect(function(hit)
 local humanoid = hit.Parent:FindFirstChild("Humanoid")
 humanoid.WalkSpeed = (speed you want here)
end)

Ok I may have found it out

apparently it is as simple as a LocalScript in StarterPlayerScripts that says:

Humanoid:SetStateEnabled(Enum.HumanoidStateType.Swimming, false)