BigE and Denny thanks for the info.
The only reason I was leaning towards Imron is that is what my painter likes to paint with. However he could not answer the question regarding below the water line.
I will let my painter know that Imron is out...I already have a paint that is in the same family as Sunfire and Signature, plus I can get it locally and don't have to put up with Tom trying to sell me stuff I don't want or need.