First are we talking about a boot stripe, or a cove stripe? If we're talking about a boot stripe, Sailingfool is right, a fixed width tape will need some modification fore and aft to look acceptable, and even then, it may not be too acceptable... I submit exhibit A:
I had to refurbish my bootstripe and had a tight time budget, so rather than masking and painting, I taped. Next time, I paint.
Usually, if it doesn't stick it's not the fault of the tape, but the fault of the prep. You have to make sure the surface is CLEAN. No wax, no dirt, no chalk. Then, when you lay it down, you have to burnish the tape as you go, to make sure it is fully adhered to the surface, with no air bubbles.