The instructions from blowsion are straight forward.One thing l did on my first scupper (blowsion) was to leave the cap that goes on the end inside the hull off.Try to put the pvc as low as possible.As far as alignment,take a grease pencil and draw a straight line from the rear of the ski all the way to the bulkhead on the side and also one on the bottom.This will give you a better shot of getting it where you want it to be.lf you have a bilge,keep it.NEVER trust a scupper not to leak!