Hi Matt, here is one procedure that might help get you started.

To begin with, I used Draw curve / Freeform / Control points to draw one profile curve. Notice the dashed line down the center - that is a construction line that I created by doing a click + hold down and drag through the origin point. That creates a guideline that you can use to snap on to as a central axis line:



Then I mirrored that curve - these will form 2 rails that you can use for constructing a sweep.


Now for the other profile - to draw this one I switched to the front view and drew this:



Then I mirrored this, selected both pieces and mirrored again, then used Edit/Join to make a closed curve. This is the profile for the sweep.

Then select the profile, run Construct / Sweep, select the 2 rails, and that will build this shape:



So that's pretty surfboard-ish! one thing that is not quite right is that the thickness is pretty variable. It is thickest at the profile shape and reduces in thickness as it approaches either end. You may want to put in some additional sections to control that and make the thickness more even through most of the board and only allow it to taper down fairly close to the ends.

You can also add additional sections if you want to have more control over sculpting the final shape.

The resulting model file is attached here as surf.zip .

Hope this helps!

- Michael