[Marico]

I'm planing a small trip to the clouds, apart from the others aspects how safe is diving into the cloud from FC (like Revo)/ESC hardware point of view (moisture)?

[TheOtherCliff]

My GPS quads often have a well closed dome for the FC and I have flown in light rain a few times.  I have never had problems with moisture.

You don't want the FC to actually get wet during flight, especially GPS flight modes or baro thrust modes that use the baro.

Some clouds can be pretty wet.  I don't think I would do it with a bare board.  Traveling through a cloud can leave visible water on things in the airstream.  On the other hand, I would bet that it would be OK if you did it.

Don't ever wash a Revo class FC.  The baro is open to the air and can have problems if it gets wet.  Salt water is a different matter.  I would feel obliged to wash the salt off.

I know there are people here that have landed in the water.  I don't know the result after drying out.

[Marico]

I know there are people here that have landed in the water.  I don't know the result after drying out.

I've landed once in the sea with flying wing and salt water broke ESC, all mosfets in motor driver circuits blowed up (I guess their gates got open  potential through water and started to conduct all in the same time making short circuit).