Carla
I have not used Interlux paint. This following method is what I used using Signature paint (similar I suppose):
Tack Rag the surface first. On a verticle surface I used a foam roller rolling from the bottom up (chine to rub rail) each stroke. Never stroke horizonal or from the top down (this causes sagging or runs). A foam brush pulled along the edges and tight corners first. After approx 2' of coverage I rolled back over with a "Dry Foam Roller" this smoothes out the roller lines. Don't go more than 2' as to prevent setup of the paint.
continue ----> drag brush edges---> roll wet paint bottom to top----> smooth out with dry roller............. a couple of days after the final coat, I sanded with 1500 grit wet/dry and buffed with 3M Perfect-It. This rid any undesired runs, bug doo-doo, heavy strokes or orange peel.
Now "Fellowship" has experience with Sterling brush & Tip. He can give some pointers also I'm sure
Good Luck