looking @ a boat with a dominator it looks like from the pic it is similar to a berk. anythoughts about this pump would be helpful

The Dominators are stupid similar to a Berkeley, good stuff and many interchangeable components, you can't go wrong IMHO

JBP could tell you for sure, but I believe Dominator materialized when Berkeley ran into financial trouble, there were a few others that sprouted up that are very similar, all at around the same time frame.

Dominator, American Turbine, Berkeley are all excellent choices as far as I am concerned. 

GT