Feathering refers to the offset of the blades on a paddle - holding the paddle horizontally one blade will be vertical while the other will be tilted at an angle. On an right hand control paddle (more explanation shortly) when the right blade is vertical the left blade will be tilted forward and the degree of tilting (the amount of offset) is referred to as the feather angle. For a left hand control paddle it's the opposite. For an unfeathered paddle there is no offset - both blades will be vertical at the same time and their is no control hand. Right hand control means that for proper technique the right hand grip stays constant on the paddle shaft while the left hand needs to allow the paddle to rotate within your hand (left control is the opposite). It doesn't really matter if you're right or left handed but it's often more natural to let your dominant hand be the control hand. Though left hand control paddles are much harder to find so you lefties might just want to go with the right hand control to make your life easier in the long run.
In whitewater kayaking there has been a trend to smaller feather angles - or even completely unfeathered paddles. A lot of this has to do with playboating where unfeathered blades work well in certain tricks. This type of paddling is very different from your basic forward stroke so it has different requirements. But the low angles have spread to the rest of the whitewater community, often for no good reason. Though it is also true that lower angles will work for folks with poor technique, an unfortunately large segment of the population. Higher angles work best for forward paddling but can make some other techniques a little trickier so most folks cap out around the 45 deg. mark.
|Low Angle Sea Kayaking|
|High Angle Sea Kayaking|
The key take away is to think about what type of paddling you do, what type of technique do you use (or aspire to use) and make sure your feathering matches up with that. Don't just go with whatever paddle you happened to buy before you knew any better. Don't just copy the fastest guy in your paddling club. Don't just listen to some random guy spouting off on his blog. Actually analyze your stroke and wrist position and maybe try some different feather angles and see what works for you - which means is easiest on your joints. That's the ultimate purpose of a feathered paddle: to allow you to paddle without pain. As long as you can do that you are good to go.