DISAGREE.....
...lots of blister jobs last much, much longer than that, if not indefinitely. And, there are quite a few yards that will give you a ten year warranty. The epoxy manufacturers can often point you to a yard in your area that will warrant its work.By the way, the things that seem to affect the life of the blister job include using at least 20 mils, up to 40 mils of thickness. Many yards and do it yourselfers use quite a bit less, but the yards that warrant their work go for 20 mils plus. It also very important to maintain a dry bilge, or epoxy it, as well. Finally, research indicates that it is a big help to epoxy at least six inches above the waterline, although this is infrequently done. At least take the epoxy to the top of your bootstripe, and then re-do the bootstripe. If you only go to the waterline, the laminate will still be exposed in a very humid, and often wet area. Good luck. Using these techniques, I am almost at the eight year mark of tropical sailing since my do it yourself blister job...with nary a blister, so far, knock on wood!