Don't back your trailer tires past the end of the dock, that's where the cement ramp ends. Keep your outdrive or engine trimmed up as far as possible until you get to deep water. It should be better now that the waters up a little bit.
I have an 18' Bass Cat and didn't have any problems.
Launched there about 3 or 4 weeks ago and managed to catch 2 small salmon up by the power plant but walleyes should be taking off now.