Knowing your Paddle Board Center Fin

center box fin triangle isle flatwater paddle board
Center Fins influence almost everything in regards to your paddle board’s stability, maneuverability and overall feel. The number one question we get at Isle is where do I place my center fin? And the number two question is what type of center fin should I get with my board as an upgrade.

In this article we will explain our standard center fins included with the paddle boards we offer along with upgrade options for the more serious paddler.

Fin Terms

Cant: Cant refers to the angle of the fin in relation to the bottom of the board. A fin that sticks straight up (90°) is said to have no cant and generates more speed than a fin with a lot of cant. Canted fins lean towards the outer rails of the board and are more responsive with turns.

Flex: The Flex can also be described as the stiffness of the fin and plays a big role in the way the board will handle the water. A stiffer fin will give the board more stability but will be more difficult to make a turn. A fin with more flex will be better responsive to the water because it will flex with the water.

 Drag: Drag is created by friction and the larger a fins surface area the more friction that is generated. Drag is what slows you down and the force that decreases your speed.

What position should I put my center fin?

Fin placement can drastically affect the maneuverability of your surfing, the tracking of your racing and the stability of your flat water tour. Although these are suggestions we recommend that you test the different placements for your own unique position as it really varies by board and rider.

Fin Totally Forward: Placing your fin forward will put less pressure on the tail of the board which creates more maneuverability and a quicker turning radius. If you have a three fin set up (thruster) then having the middle fin placed forward will channel the water in a concentrated area and could potentially slow the board down while surfing. That said, if you are looking for less hold and a shorter turning radius then moving the center fin closer to the nose is the answer. 

Fin Far Back: Positioning the fin towards the back of the board will result in more stability, this is because the fin is rigid in its line. More importantly, the board will track better opposed to the other placements because it gives more restraint to the tail.

The Happy Medium: The happy medium is always a good default position, it is a balance between control and stability. This placement is the most widely used because of its versatility between turning, tracking and steadiness. If you are surfing and using a thruster then you want the center fin about 2 inches behind the side fins which allows enough spacing for water to flow around the fins.

Categories of Fins  

The design of the fin will affect the speed, stability, tracking and maneuverability of your board. There are specific fins for particular purposes of paddling and fins can be broken down into these following categories:

Isle team riders paddling with race board and touring board

Race: With racing a paddle board you are concerned about two things and those are, tracking and speed. As a racer you want to minimize the number of times you switch sides and maximize the amount of strokes on each side while staying in a straight line. With that said, you want a fin that has a lot of surface area to keep you stable and improve tracking. Furthermore, you want a fin that doesn’t have a lot of drag and is short enough to do a buoy turn.

isle race stand up paddle lake Havasu

Touring: Touring fins are designed for one thing and that is to go as straight as possible. Since touring is all about going the distance you are looking for fins that have a wide base with a longer leading edge which helps stabilize the board and assists in choppy water and swell.

getting barreled with the isle phantom classic in Indonesia

Regular/Surfing: Racing and Touring fins tend to be longer for tracking purposes where surfing fins tend to be smaller for maneuverability. Traditionally, paddle boards used for surfing will have a three fin set up with the center fin and two smaller fins on the sides (side bites). The reason for this is that the side bites will channel the water and prevent your board from slipping sideways down the face of the wave. The center fin for surfing is there to stabilize the board and controls how the water moves under the tail of the board.

Types of Fins

Isle All Around:

isle all around fin

The Isle All Around is your standard fin that comes with all boards excluding the iSUPs. This fin is made out of plastic and has an evenly distributed amount of surface area which can work in all types of paddling.

Isle Keel:

iske keel fin

The Isle Keel fin is included with all touring and race boards. This fin has more surface area than the Isle All Around and will be more firm in the water providing great stability.

Future Triangle Cutaway:

futures triangle cutaway fin

The Future Triangle Cutaway is made for the experienced paddler and a perfect choice for touring because it works well in all conditions. The swept back leaning edge cuts through kelp and weeds while the 55 square inch surf fin shape is deep in the water and offers great stability.

Future JB Keel:

Jb keel fin futures

For the experienced racer, the JB Keel is a great addition because it has a sizable 58.9 square inch area that gives optimum forward drive while stroking. This fin will help increase the number of strokes per side and more controlled tracking due to the large surface area. It has a laid back leading edge which keeps your fin free of kelp and weeds.

Downwind:

downwinder fin futures

The Future Downwind is designed for maneuverability, the area is distributed throughout the fin which helps with bumps, white caps or while surfing. The middle part of the fin bulges out to help with the board getting pushed side to side by the wind.  The Downwind has a more upright design allowing the board to pivot more cleanly.

-The Test-  

an array of fins to choose from for all paddle boarding needs

Now that you know all the terms, placement, and types of fins do they really affect your tracking? We wanted to put it to the test so we designed a controlled study that took place on a 1/10 of a mile course where we utilized all four fins and used the three placements to see if there was any differences. The course started in the water going against the wind so it would attest to the tracking of the fin due to having an external force pushing in one direction.  With our 11 ft. Glider Flat Water we put each fin in all three placements to see the discrepancy in stroke count, tracking and overall feel of the different fins.

paddle boarding around the Coronado Bay

No Difference in Placement: After placing each fin in the different positions (front, back, middle) we observed how there was little to no difference with the position of the fin in flat water over a short distance. Although, we did not test this in other conditions such as open ocean or competitive racing we presume that the 1-3 inch difference in placement is negligible.

More Area, Better Tracking: What we did conclude was the larger the surface area of a fin the better tracking the board will have. This is because, the more surface area in the water will guide the board in a straighter line than less surface area. Although when you have too much surface area you could create enough drag to slow you down. This is because the more surface area there is the more friction is created which causes drag and consequently slows down the board.

Data:

All around Fin:

  • 37 strokes
  • Tracks well: 3 -4 strokes per side
  • Buoy turn felt easy

Future triangle:

  • 38 stokes
  • Tracks well: 4 stokes per side,
  • Felt like it tracked much better up

Future Keel:

  • 41 strokes
  • 5 per side
  • Felt good

Isle Keel:

  • 38 strokes
  • 5 per side

 

 

Knowing your Paddle Board Center Fin

Posted in Gear Guides
Marc Miller - Co-Founder of Isle Surf & SUP. I started Isle back in 2004 to share my love of paddling and surfing in the ocean with others one board at a time. I love to surf, paddle , travel and write about it. When im not in the office I can be found on foreign shores searching for waves and fun.

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