I've launched 16.5 Lund there many times without a 4x4 BUT water levels are critical. The cement slabs are not even and slant to the West. You can bottom out your trailer on the axel hanger bolts getting out. Other issue is your trailer doesn't sit level and makes it difficult to load your boat with out power loading. Many boaters having to do this has blown out the bottom at the base which caused the uneven loading aqrea.
My two cent worth.