I keep hearing the word paddleboard used to describe stand up paddling. That said, here's a simple translation of various terms being used for the sport to clear things up a bit..
Paddleboard - are long narrow boards where you sit on your knees and use both hands to paddle on each side of the board. See Joe Bark's site.
SUP - stand up paddleboard
SUB - stand up board
Surfski - approx 22' long and very narrow sit on top boat used for flat water racing and some surfing. Usually very light.
Waveski - high performance sit on top surfboard or surf kayak. Paddled like a kayak, used specifically for surfing. Up to 10'. See image above of Tyler Lausten (bottom), http://www.tlwaveskis.com/
Southerly - Winds from the south.
Northerly - Winds from the north.