the human analog might be,, living with an aneurysm
I am not so sure.. Maybe a flesh eating bacterium.
There are treatments and there are solutions.. Sometimes the solution feels out of reach depending on where you are and what you have.
You are looking at the symptoms. Water in the bilge. You have experienced some events. Inspection and clarification of the extent of any damage from the event would be the first step to a solution. Working on the inside is like putting a bandaid on an infectious sore. Sealing the outside and then drying out the inside would be addressing the symptoms. Removing the keel and resolving any damage would be the steps toward a resolution and possible cure. At least that would be my medical unprofessional opinion.
I agree Ralph…
The Aquamet, as identified on the site, is still a SS alloy. SS is always subject to corrosion when in an oxygen depleted environment. 316 is better than 304. As I suggested contact with the website may be able to share clarifying data as they are a specialist machine shop using Aquamet.
It seems to me there are practical limits to the sourcing of materials. 316 is a good compromise. If water has intruded beneath the hull stub shield, then the water is in a place that is without oxygen supply. SS even 316 or aquamet will act based on its exposure.
I had to replace my prop shaft when I discovered pit corrosion even though the area under the traditional stuffing box looked shiny and smooth.
This is what I found after opening the stuffing box and then sliding the shaft up the shaft log. Evil hiding out of sight.
Your shaft looks to be surviving the exposure to the elements.