I bought a boat from a private seller and was told the boat ran great. It doesn't

I bought a boat recently, about a week ago and took it out as soon as I got it. I was told it ran great from the seller and ran good in his driveway when I tested it before buying. I took it out on the lake after buying it and it doesnt run very good. Found out I have no good compression on one of the cylinders which it would need a rebuild. I thought I was screwed since I paid cash. I just found a recept in the boat from last year from the owner of the boat I bought it from saying that the boat had bad compression and in one of the cylinders and that it backfires over a certain rpm. Can I legally get my money back if I was sold a boat and was told everything worked and have proof that it in fact does not?