another impeller question

[Wpg Manitoba]

I'm not sure what to do, I think I put the impeller the right way but I'm not 100%. Its seems to be pumping fine so I thought it was in the right way. I guess my question is if the impeller was put in backwards should the waterflow be noticably lower?

[boats.net]

It may or may not be noticeable. If unsure drop lower unit and check it.