bobad, pressure treated lumber will not rot easily in or out of the water. In fact, it may very well rot quicker out of the water when it dries up and cracks. I actually called up to Canada and talked to the guys that posted these plans on the Canadian Fishing Website and they have had these docks in place for 10 years with no issues. I believe the life of this dock will be in the 10-12 year range and then it will likely need additional foam or foam replacement due to deterioration and some waterlogging.
