I have a 26' sea ray and the wake is like all white wash. Basically the entire wake is this way. I have only ridden about 5 times last year and have to wait for snow to melt. Is it possible to even go wake to wake on a completely washed out wake? I was at about 18mph also. The boat has a 454 and also has trim tabs. Does running the tabs down help clean it up? What about trimming the drive?
Trim your drive until it starts bouncing, then back off just a hair. Also you could try adding some ballast to the rear. I have a 21' i/o and use 1 500# sack. It really cleans up the wake. Also try adjusting your trim tabs. Should work...good luck