Why is it important to know your surfboard
If you view your board from one design perspective, you gain a deeper understanding of the whole design and how it wants to be ridden and what style of surfing it will produce.
How are you supposed to use it, if you don't know how to use it? You could have a magic carpet of a board and not even know it.
If you don't know the functions of a surfboard and what the board is designed to do, it's like giving your grandmother a Ferrari and she only drives it in second gear. So step back away from a surfboard and look at a radio or your car stereo. You've got a few buttons, Bluetooth, aux, cd, tuner, skip, volume, power etc. If you don't know half of those functions and how they work, you're stuck listening to classical music or talk talkback radio on AM Radio. (sorry if that's your jam - not mine)
So how do we learn to use our boards better?
Everypart of a board is designed to turn, or hinder turning
Length, width, thickness, rocker, outline, tail shape, nose, concave, etc. all impact the way that the board feels and turns.... or doesn't turn.
The kicker is... everything is a trade-off in board design.
There's a real trend for wider and fatter boards right now. More average surfers than ever before and everyone just wants more waves. Nothing wrong with that, but what do you lose by gaining more width and thickness? You dull the feeling of that board and how well it can turn.
Mechanics of turning
Just quickly, to turn the board, you have to put it on rail. To do that, you have to lean or put weight on the rail to sink it into the water. The rounded edge of your board rolls and the water hugs the rail, whereas a hard edge will slice the water (this is used on the tail for release). The bottom power zone will interact with the rail, rocker and outline, causing the board to turn and accelerate.
The trade offs
So if you have a wider board, you have a bigger surface area of water that you have to push to roll that rail, but you gain more stability. If you have more thickness, you have more bouyancy and the board want's to float more. So you have to push harder to roll the rail.
The vast majority of your board channels water along paths within the board, nose, tail, outline, channels, concave. Either affecting that water flow or adding more or less surface area. Add more foam, less foam, edges, deeper concaves etc. It all affects the ability to turn. Yes, a lot of these impact speed and stability but I want you to look at your board from the viewpoint of how well does it turn?
Boards that don't want to be turned
Right, you may be reading this and thinking, but I have a board that's designed to go straight and not turned.
That is true, the point of this is to view your surfboard from one aspect, that is, turning, and you will gain a better understanding of how that board works and what it wants to do.
So if you have a board, say something just for ridding barrels, you want stability more over turning. Then from this lens, the board is still designed for turning, but it's been designed to not turn well. It doesn't want to turn as well as say a standard high performance shortboard.
Or look at a nose rider, designed not to turn like a high performance longboard. Stability and control is what the main design of it is. A tail of a board designed to turn will have a flat edge to the rail around the tail to help release water and come out from turns. Think rail to rail. Now a log doesn't want that. To nose ride, the tail needs to hold in the pocket, it needs rounded rails that the water hugs to. So still, the board is designed from a turning viewpoint but minimising the ability to turn to favour nose riding.
Go have a look at your own board and try to understand how well that board is designed to turn. Now, take one element, and change it. How will that impact its ability to turn? For example: make it longer, it will have a wider turning circle and more drawn out turns.
Now how does that fit into what you are working on in your surfing? Good or bad? More feeling or less?