manni-yunk
Contributor
I've had 2 plastic housing UK dive lights flood in past years. None of my aluminum dive lights have ever had an issue.
comparing apples to oranges.
I doubt they flooded due to them being plastic, unless you actually broke the body of the light - which would be described differently than just flooding. Most lights flood do to a bad or misplaced o ring, or some sort of o ring compromise.
Delrin, aluminum - really doesnt matter. They are all corrosion resistant and will stand up to abuse. Its all personal preference.
One advantage I can think of, for HIgh powerful lights - is that with aluminum, I think it offers better heat dissipation if used in the head VS delrin.