I would put it above the rub rail, simply to avoid having it damaged when they dock. Keep in mind that Triumphs are a polypropylene hull - it's going to take extra steps to get the decals to stick. In the past I've prepped with alcohol, let dry, then flashed the area with a torch and immediately put the decals on. Don't try to do this in weather like we're having - it needs to be warm.