This weekend I borrowed a friends "decal eraser" to remove the sun-baked decals off of a Hobie Tiger and couldn't believe how well it worked. It is just a rubbery disk that you put in an electric drill and touch to the decal. The results were amazing. I had first tried the traditional methods but they were so brittle that they would just break off in tiny pieces. I did six decals including the large "Hobie Tiger" on the sides in about 10 minutes, then spent another 15 cleaning off any remaining glue residue with some thinner. Do a google search for "Astro decal eraser" to see get more details. I have no affiliation with the company.
1989 Hobie 18 Magnum "Rhapsody"
2007 Hobie Tiger