When you really think about it and boil it down, kayaking is all about connections. They may come in big picture form as well as technical skills. Connections between you and the forces of nature. You and your stoke for the sport. You and your paddling buddy. You and the present moment. Your connection between your body and your boat. You and your paddle. Your paddle to the water. Connections are everywhere in whitewater kayaking.
For this week’s edition of Current Connections, we are diving into the connection between the boat and the water.
Displacement hulls, planing hulls, primary/secondary stability, chines, double chines, bow/stern rocker… What does it all mean!
Boat design has come a long way over the years. Fortunately you don’t need to know all the physics that inspired the designs above. You should however take the time to explore how various design features affect the handling of your boat. Here is your Boating Lab Assignment! If only school was this fun!
Purpose: To explore how six types of movement change the way your boat interacts with the water.
The six types of movement:
Side to Side
Hull Speed – This is the difference in speed between the boat and the water. Notice that this is a relative speed. Think of a time where a boat may be still relative to the shore and still have significant hull speed. Think of a time where your boat is moving quickly with no hull speed. Is there such a thing as negative hull speed?
Roll, pitch, and Yaw are “engineering/aviation” terms often used to describe rotations around the three axes of 3D space.
Roll – Rotation around the axis going from bow to stern… think about edging your boat right/left
Pitch– rotation around an axis going from side to side… think about weighting the bow or stern
Yaw – Rotation around the axis going though your spine… think about a spinning or twisting motion like torso rotation.
Translations – In our minds, we often imagine kayaks tracking around turns like a car, but even a cursory inspection will reveal that we are often just sliding around! Once again, this movement is relative and happens on the moving surface of the water!
Translating Forward/Backwards – Water sliding under your boat from bow to stern
Translating Side to Side – Water sliding under your boat from right to left
Your boat is your best learning resource, you can ask it questions by altering any one of the six types of movement and it will respond honestly and promptly (sometimes a little too honest and a little too prompt). Your job is to interpret the feedback from your boat to gain insight. Spend some quality time in some calm water and contemplate some of the following questions?
- How many strokes does it take to get up to full speed?
- Is bow angle easier to control when the boat has more or less hull speed?
- Is bow angle easier to control when hull speed is increasing or decreasing (think acceleration)?
- How do you think pitch affects your control over the bow angle?
- When gaining hull speed, when does increasing effort have diminishing returns?
- At what hull speed does your boat begin to plane on the water?
- How does hull speed affect the way your boat carves?
- How does roll affect the way your boat carves?
- How does pitch affect the way your boat carves?
- How does yaw affect the way your boat carves?
- When is side to side translation useful?
- How do Roll Pitch and Yaw affect side to side translational movement?