I am trying to find some sort of support stand for my boat. I have a 18 ft boat and the only place I can store it is in my drive way. The problem is that I have about a 15-20 degree slope to my driveway. I need to be able to jack the tongue of my boat up at least 40+ inches in order for the boat to slope rearwards for draining purposes. Now what type of stand out there will work on a sloped concrete surface and support about 300-400lbs while being able to jack it up that high also? I have looked at getting one of those farm/offroad jacks to get it up there but still need some sort of stand/support to keep it up there and stable at that. I would like to be able to still climb in the boat while in the driveway on the stand. Right now I have a somewhat temporary riged solution and I am looking for something a little more stable and suitable for long term storage.