SUP Paddle Shaft to Blade Offset Angle

I enjoy being a part-time SUP instructor.  I feel honored to be able to introduce this sport to people when teaching for Blue Waters Kayaking on Tomales Bay or California Canoe & Kayak on the Oakland Estuary.  The people that stick with the sport will always remember me as the guy who gave them their first lesson just like I remember the guy that gave me my first lesson at Outside Hilton Head about 5 years ago.  

During my lessons, I like to do a little introduction on the beach.  I briefly talk about gear before moving on to what we are going to go and where we are going.  I spend most of the time talking about the paddle, the parts, the length, how to switch sides, etc.  I make sure to show them that the paddle blade is offset from the paddle shaft.  I tell them that this offset helps them pull the paddle from the water to begin the next stroke.  Normally, that is enough.  The point I want to get across to them is that during the lesson, they are going to have their paddle facing backwards!  Oh the horror and embarrassment!  

There's only so much data a person can process while standing on the beach anxiously awaiting their first lesson so I try to keep it brief.  In my head though, there are thoughts of keeping the blade vertical for a longer period of time during the power phase, increased reach, and improved caster, and less board heave.  If I'm not careful, I then start thinking about how my paddles have different offset angles and what that means which leads to thinking about the new Werner Stinger that I tried last weekend with a measly 7 degree offset and why that would be advantageous for whitewater paddling.  I'm slowly learning to keep my mouth shut and to move on with the lesson and not rattle off why the Werner Stinger has 7 degrees, my Werner Nitro and Spanker have 12 degrees, and my KeNalu Molokai has 9 to 6 to 3 (at the tip) degree offset and why I like the Nitro for surfing but it's not because of the angle, it's because of the blade shape and size as compared to the larger and fatter Spanker which looks similar to the KeNalu but I like the KeNalu better for downwinding because it seems to flex a little bit more because of the smaller diameter shaft and how much I like the lighter weight and the way the non-power face of the blade helps me brace blah blah blah.  At this point in their life, they DO NOT CARE ABOUT THAT! 

I can't help but think though, why ARE these paddles "bent".  Where did it come from?  I found a really good article on the Mad River Canoe website that explains all of this a lot more.