this is my first post here, thanks in advance for any help you can render. I am working on a project that turns on one 5mm white LED running on a 3.7v lipo battery when it comes in contact with saltwater. I want to mount this on my dock pole so when the tide comes up I can look out my window at night and know its high tide. I want it to be as small as a package as possible. I have a Suunto mosquito dive watch that has some sort of water contact in it that turns on automatically when I go diving. This is the same kind of approach I am looking for.
I have searched the internet for days looking for mini water contactor, micro water contacts, submersible underwater nano switches, etc. to no avail. What is the best way to make this happen. I don't want to have to use a micro controller. If I could somehow modify a mini led flashlight by adding a water contact that would be suffice.
So the question is what parts I could use to get it done and where to get them.