My buddy and I manage to screw it all up today.  Here's the tally:

•  Hitch pin fell out (or was never inserted), dropping the trailer on the way to the ramp
  
•  Boat proceeded to put a nice dent / scratch in his shiny 2005 Frontier tailgate since this was used to stop the boat
  
•  Brand new drain plug was found to be faulty - once we got to the river
  
•  Motor ran us up the river fine, then refused to start again
  
•  I fell in the water trying to load the boat
  
•  Didn't catch anything but a stiff breeze
  

Lucky for us...

• Some nice folks saw our trailer trouble and ran to get us a new pin
  
• I was able to jury rig the drain plug
  
• We decided to run upstream instead of down
  
• When I fell in water was only knee deep
  

LOL.

Well, as the saying goes..."a bad day of fishing is a whole lot better than a good day of work" ;D

Haha, better luck next time!

About a year ago I loaded up and got to the lake and proceeded to put in the plug when suddenly I could not find the blasted thing! I had to go all the way to town and pick up a plug and then drive back. About a month ago I was cleaning the boat and the plug magically reappeared! Now I have 2. :-?

I've done almost everything you mention in your post...but never all at once! Tough day, glad it didn't ruin your sense of humor.