I'm curious if I recieved some bad gas yeasterday. The day prior I was able to get 4900 RPM's @ 69 MPH out of my boat. Yesterday I filled my tank with 70 gallons of ethanol free premium and expected at least the same power. Instead I got 4200 RPM's and 65 MPH. I did switch the rotation of my props to in vs out but other than that all else was the same. The boat is a Formula 292 Sr-1 and the props are hydromotive QIV's. Most people with this combination see a 2-3 mph increase when spinning in. So my question is the problem bad gas? If so it there any way to be positive about it.

any luck?

You just add over 500lbs of weight , of coarse it's going to run slower.

You changed two things at once, without testing in between, boating no no

At the very least I would switch the props back just to see. You may also want to change or dump your fuel/water filters. Ethanol leaves a thin fuit roll up like film on the inside of the tank when it sits, you may have broke it down with the fill up and caused it to clog the filters.

Do you normally run premium fuel???? If you don't need premium, then it will actually make less hp than regular 87. It does not burn as completely.
I highly doubt the fuel is bad or you would have other issues.