Give the Man a Fish: Nose = 18" @ 12", Tail = 15.5" @ 12", Midpoint = 23"
Teach the Man to Fish:
Here is an alternative method that I use to get dimensions from pics. It is probably almost as accurate as blowing up the pic and if you have Microsoft Paint (which usually comes standard with Windows) then that is all you need. This is not NEARLY as complicated in the doing as it is in the describing so don’t get intimidated by the following (I have never been accused of being succinct). Also  here is a hint  the “View” menu in the top toolbar of Paint lets you Zoom In to enlarge pictures so you can really get details.
1.Right click on the pic and copy it.

Open Paint and paste the picture. It will be converted into a bitmap format when it pastes in.

Now, put your cursor anywhere in picture and look down in the right hand corner just above the toolbar. You will see a number with up to 3 digits, a comma, and then up to 3 more digits. For example, 379,842. The first set of digits  e.g. 379  give the horizontal position of your cursor. The second set of digits  e.g., 842  give the vertical position.
What I usually do is find a picture of the board that is taken so the stringer is perpindicular to the ground  just like the pic you posted. I then draw a horitontal line across each end of the board that is perpendicular to the stringer and a vertical line conecting the two end lines.
Get the coordinates for each point where the horizontal line intersects the vertical line. Taking your picture, I get 262,41 as coordinates for the nose and 262,607 as the coordinates for the tail. Notice that the first set of numbers  262  does not change because you are moving in a vertcial line (i.e., the stringer) from nose to tail but you are not moving horizontally. Now, determine the “difference” between the two sets of vertical coordinates by subtracting one number from the other. In your case, 60741=566. This means that there are 566 “units” between the nose and tail of the board in your picture. Since you know the board is 11’1, or 133 inches, each of inch of the board must constitute 566 / 133 = 4.256 units. From there, you know that one foot (12 inches) is just at 51 units.
Repeat this general process to get the tail and nose. Add 51 units to the vertical coordinates of your nose (41+51 = 92) to get the vertical position of the 12" (nose) point on the board.
Subtract 51 units (60751 = 556) to get the vertical position of the 12" (tail) point on the board.
Draw horizontal lines from rail to rail (i.e., lines perpindicular to the stringer beginning and ending at your rail lines) to get nose and tail width.
On your board, I get nose coordinates at the 12" mark of 224,92 and 300,92. This time you will use the first set of numbers  the horizontal coordinates  and repeat process by subtracting. Here, 300224 = 76. The nose of the board is 76 units wide, which means 76 / 4.256 = 17.85 inches. Owing to human error in drawing my lines, the fact that the picture was blurry, etc. I would be willing to bet that the nose was either 17 7/8" or 18" wide.
Doing the same for the tail, I get coordinates of 226,556 and 292,556. Determining the spread in the horizontal coordinates, I get 292226 = 66 units, or 66 / 4.256 = 15.50 inches for the tail at the 12" mark.
You can use the same general process to determine the vertical coordinates of the midpoint and the width at the midpoint. Because I am getting ready to go for a surf, I will spare the description and just tell you that I get a midpoint width of 23 inches.
I will leave it to you to determine placement of wide point (hint  think tangents) and width at widepoint.