I would try detailers clay on your boat and truck. If that does not work, youll need to use some sort of solvent. Some of the big car parts stores carry a product made by Stoner Solutions its called Tarminator. This works extremely well. Just spray it on, let it dwell for a few minutes, you should start to see the tar starting to run, then wipe off. It may take several applications. Ive detailed cars that are covered in tar, its a slow long process.