I have made some videos about moldinjection a skimboard.
Moldinjection is is what your dealer will sell you in two years for a zillion.
I have been choosing a skim because it is easy to build, no need to have a mold and yesss I need one of this strapless puppies but check the vids and you will see, This is the first one in a large set.
I also have started a mold HowTo, like all the stuff I build, it is slightly different. You will find it in the section HowTo Mold
And last but not least I run a planet for kitesurfing, with around 200 articles as per today.