Ahmed, on my pier I have put a wardrobe dehumidifier tub next to the mount covered with a thick plastic rubble bag and the final cover is a waterproof tarpaulin cover with handles. All held down with a bungee cable.
I have no moisture on my mount or signs of rusting.
However two things get removed after a session, scope and camera.
I have a small keter storage shed, which inside has a 105ah leisure battery on a trolley, which all my power is supplied from. The only thing I need to do is unreal one cable wrap with all my power connections included inside of it, plugin and off I go.
Welcome to come and see Ahmed.
Nadeem.