Photo proof that early windsurfers were the original "reinventors" of sup?:

[clayfeeter]

Hey guys, early windsurfers were sup'in outta neccesity when the wind died:
          clay
          www.standupjournal.com

[PonoBill]

Been there, done that. Many times I paddled my windsurfer back in using the bottom section of the mast. Surprising how good of a paddle it makes.

[DavidJohn]

Back well over 30 yrs ago I raced the very first windsurfers with the big triangle sails.. wood booms etc.

I remember one day we were waiting for some wind to start our race and someone just mucking around took his big wally windsurfer out sitting on it and paddling with just his mast on the glassy smooth water.

We all watched as he stood up and paddled it with his mast and it wasn't long before we were all out there paddling around and having a ball.. I was surprised at just how easy it was.. and how much fun it was.. 

DJ

[wavehobbit]

Thank God for the SUP though.  I have to laugh at the guys who ask about the using the old windsurf boards as SUP's.  Hey, I've surfed my windsurfers a few times just fooling around or the time I forgot to pack my shortboard on a trip.  It's dooooo-able but pretty funny,,,those rails kill you though.  Once when I was stuck in a lake in LA and I'm not talking the west coast, I surfed a Mistral Superlight all day behind a friends boat wake.  No tow rope, just paddle in as he motored by at 8 kts.  It was a blast but when I'd walk the nose, the board would speed up and race towards the outdrive.....Can you say drop knee cutback and quick !!!!  Tinho D down in Cocoa has been doing it for awhile.  When I went to get my windsurf instructor cert, he was SUP'n an Equipe I think while yelling instructions at as.  That was in 91 or 92 I think.

[Weasels wake]

A bit old but pertinent to the current line of thought 

Stand Up Paddle Surfing a 7 Foot Board on Maui