A Lengthy Answer

The most frequent question I get is "how do I determine paddle length?" Well, I'm sad to say that it's not a science but there are some general guidelines. There are a few factors that could impact what length paddle would best suit your needs, including the type of canoe you plan to paddle and what position (bow or stern) you typically sit in. If you're brand new to marathon canoeing, the Seated Chair Method (see below) will give you a good starting point.

 Seated Chair Method

Let's run some scenarios.

Lets say you have a 30" seat to nose measurement which gives you a suggested paddle length of 48" (30"+18" = 48"). If you are used to wooden tripping paddles, 48" is going to sound really short, but there are 2 good reasons for this. Firstly, a shorter paddle allows for higher stroke rates to occur naturally. Just imagine a child on a swing that has short ropes; they are going to naturally swing with a higher frequency. This higher stroke rate allows you to input smaller amounts of force more frequently in order to keep the boat moving and over time this is much easier on your body than the alternative. Secondly, the shorter paddle keeps your top hand at or below eye level, which is much healthier for your shoulders. 

As a reference, I'm 6'1" and my seat to nose measurement is 33" which would suggest a 51" paddle. This would be close to what I would typically use in the stern of a C2 (tandem racing canoe) but in the bow I prefer a 49-50" paddle. In a C1 (solo marathon racing canoe), I may go a bit longer than 51" to get a little bit more reach in my stroke. Here I would use a 51.5" or 52" paddle. 

You're probably thinking...what if I get the length wrong!!! It's pretty easy to shorten a paddle, but a lot harder to lengthen it. So when in doubt, buy it a little bit longer than you think you'll need. See my section on "how to shorten a paddle".