What Impacts Paddleboard Stability

10 Mar 2023

Stability is the first question for many people when thinking about a new paddleboard. Whether that be for a newbie or a seasoned pro, the question of stability will nearly always come up as it greatly affects the paddling experience.
But what impacts a board's stability? The obvious answer and the one most people think about, is the size. And this is absolutely correct; the size significantly impacts stability, but it's not the only attribute, and it is the one that comes with a compromise.


There are actually four elements to a paddleboard that will directly impact its stability. And while very few people consider the other three, each of the following attributes affects the boards' stability in very noticeable ways and should be considered equally.



1. Size 

Maybe this one doesn't need a lot of explanation, but we didn't think we could leave it out of the discussion based on an assumption of understanding. This is for a couple of reasons. The first is that beyond the boards width, the length also plays a role in providing stability. It is both the boards length x width that will add to how stable the SUP will feel. The trade-off of this, though, is maneuverability. The larger the board, the less maneuverable it will be. And so, when looking at a large board only to provide the stability a beginner might want, these boards can sometimes become big, slow and cumbersome once the paddler becomes more confident. And this is why the next three attributes should also be considered.



2. Rigidity 

Rigidity is the second on the list for a good reason. It is the board's rigidity or lack of it, that will render a board's size (the first consideration) less effective. And you can often see this down at your local paddleboarding destination. You will see a large board, often quite thick, that bends a lot underfoot. Making the board bend in a weird V-like outline.
When your board bends in this way, it renders its size ineffective and makes the board terribly unstable. When you see the folks on boards doing this, you will nearly always see them struggling to be balanced, stable and confident on the board. It looks like a battle...because it is.

The more rigid your board, the better all that size is for stabilising you on top of it. The board moves in a more predictable way, and better resists the ebbs and flows from both the paddler and, of course, the water itself.



3. Thickness 

Probably the most overlooked feature of a board is its thickness. Holding all other things equal, the thinner the board, the more stable you will feel when you're on it. The reason for this comes down to the relationship between the source of the instability, the water, and your centre of mass.
Put simply, the closer you stand to the source of instability, the more connected and, therefore, stable you will feel with this movement.

But... and there is a big but with thickness. Like always, there is a trade-off. A compromise of performance that is immutable. And that trade-off is rigidity. Remember the point above!
If making a board out of identical materials and construction, a thinner board will be less rigid. So what this means is that you must balance the thickness with rigidity and size carefully.
But not wanting to make this more confusing than it needs to be. What is important to know here?
Simply this; Look for board materials and construction that balance thickness and rigidity well. You want thin and rigid.

Not thick and rigid, OR thin and bendy.
Both of these options will feel quite unstable.



4. Fin Setup 

If you ever wondered why surfers make so much fuss about fins and wondered if they really do much at all, you should take your board out without any fins. It will clear it up for you very quickly :)
Fins and fin setup are integral to how a board will perform and how stable, fast and maneuverable it will be.
And we will get the big question on "Side Fins". What are side fins for, and do they make my board more stable and why don't we have them on nearly all our boards... We will come back to this after we talk about specific impacts on stability.

The most effective fin for stability is your CENTRE FIN.
A large centre fin will provide the most amount of stability. this is because it is effectively a big paddle sticking out from the centre line of the board. So when your boards rocks side to side, it does this over the centre line of the board, and to do this, the fin has to push squarely against the water. Hence, creating resistance to this movement that you feel as stability.

This is where you see side fins in addition to a large centre fin. Technically speaking, this setup is slightly more stable than the single fin, but this incremental comes at a significant cost to board speed. This is because these fins should be turned in towards the nose as their purpose is to help the board turn when on the rail. This is normally achieved when turning on a wave. So when paddling along on flat water in a straight line, these fins create drag and provide very little extra stability. This is why most Honu boards don't have side fins.

Next on the list is TWIN FINS.
With this setup, you have two medium-sized fins offset from the centre of the board. This fin setup does provide stability, but noticeably less than a single fin setup.

Last on the list is a THRUSTER FIN setup. This is the setup where you have three medium-sized fins setup in the same pattern/position as the 2 +1. The difference being all three fins are the same smaller size. This setup provides the least amount of stability and in general, is reserved for surfing SUP's.



Wrapping it Up 

As you can now hopefully understand, there are several factors that impact a board's stability. Making matters more complex, these factors have trade-offs and also affect each other in several cases. But the main takeaway here is that you should think beyond board size, as this is just one of four important features of a board that will greatly influence how stable the board feels out on the water.