My setup is a twin drive, rams on inside of drives with the Tie bar.
The port side has 'always' created a small light sheen in the water when sitting.
i have never had water in the system, however I have always had to add power steering fluid.
This was from brand new and they could never find it. Well they only checked it twice

How does one 'hunt' down a leak?
Or do you just rebuild the ram and hope you correct it?
Are they rebuildable, and can it be done with standard tools?
I beleive it is an Imco system

the oil you see on the water is from the rod on the ram. all hydraulic rams have a little oil on the rod from the wiper in the ram. if the problem gets worse you will have to replace the wiper seal in the ram.

I can understand that.
However then why only on one side of the boat in the water is this sheen?
It is obvious I have been losing fluid hence the refilling.
I just cannot find it.
Is there a die that I can add to the fluid to help?

What about when it is out of the water? Can you run it on the hose and look for leaks? Maybe at one of the fittings or leaking hose?

I run Tranny fluid in my steering,,,red ,,,i always see when there is a leak and never had a problem with the wiper seal.

No oil here ,,,s i would add some red tranny fluid and check it again ,,maybe u see where its coming from.
I also think it may be a fitting on the ram, not so much the ram itself.
Rebuilding,,,symple, reg. tools and orings from the hardwear store. Maybe 10 bucks each ram.