I have a problem with the directional light an the underwater caustics (material: LF_Caustics_Inst).
It works probably but at any places on mountains I have the caustics shining.
The waterlevel are correct. So is this a problem at the material or at the configs?
I hope anyone can help me out 
Problem solved! If you have the same issue here the solution:
On this pic you can see the block of code in the āLF_Causticsā material-blueprint. You must change the texture of the āTexture Sampleā.
The new texture it self must have an alpha channel as mask.
Then you can draw the color as height. Red, blue and green on their own channels .
The height can configure with the parameters at R min height, G min height and B Min height.
I hope that can help you too to create caustics on your own map 
Thanks for the info! My landscape has a valley of about 1,000 meters and I was trying to move my landscape to around -40,000 Z to get some clearance from the clouds which I donāt know of any way to āraiseā to a higher Z value. Unfortunately I was noticing the same caustics and also underwater particle emitter effects. Seems like I remember about not going below -48,000 Z somewhere, not sure what other issues that causes or other issues related to landscapes that are much different scale/location from āTheIslandā.
I love seeing code with magic fudge factors 
always makes me smile. Good job finding a solution!
Hmm ok this is happening on my map as well but from your post I still cant work out how you low the height of the caustics ?
Any one shed some light on how to move it down a little 
Good news! I will try to work it out. If it works (for me), you will have done a very great job!!
