When you go longer in the surfboard, it's better paddling. And the same with the thickness, it's better paddling. Now with the area, the center, the width of the board, you can go wider in the width of the board, and you can actually drop down in size on your surfboard because you're creating more area, more planing area, so you don't need such a long surfboard.
And the same goes with the thickness. You can drop down in surfboard size, go a little bit wider, and a little bit thicker, and still have enough volume to carry you. You want to measure the length of the board from nose to tail. This board is 6'2". On the width of the board, you want to measure where the widest point of the board is. In this case, the board being 19" wide.
The other measurement that you want to know is the thickness of the board. This board is 2 3/8" thick at the thickest part in the center of the board. Now, there's two other measurements that you really want to know when measuring a surfboard. Basically, the measuring the nose is 12" down, and then across. And then, measuring the tail area, is you measuring 12" up, and across, being a 13.5" scale.
Another measurement you're going to want to know in your board is the rocker. Now, that's the bottom of the board. Now, the more rocker you have that fits into a real hollow wave, and the flatter rocker, is going to be really fun in a small, mushy surf. Now, in the tail area, you measure it right at the tip, and this board has 2.25" of tail rocker in it. Now, going up to the nose, you measure off the tip of the nose, and this has 5". And that's your measurements on your boards.