Your off-shore unit looks like it will serve the purpose it is intended for, but durability is probably questionable. I went with FlowKooler because I believe the required belt tension for the steering pump, that is nonadjustable, to work as designed is to much for the off-shore casting to withstand. I think a 5 impeller Chinese pump will cool almost or as well as the FlowKooler but I am hoping for better castings and quality control.
Mitch