check the clamps, on exhaust hose, and pipe to waterbox connector. also, check o-rings on the drain plug/s..believe size 12 at ACE.
Also, you can fill the hull up with water, nose of the boat up, just above the driveshaft area, remove the grey shield, the watch from the back and underneath, maybe might see where water leak is.
also, hookup to hose, and fire it up. Maybe leak'n internal from bad pipe, waterline, hose clamp, waterbox,...then repost