Replying to water ramp help...

My friends and I are putting together a water ramp this summer. We have the perfect place (my friends grandmas lives on lake superior and has a 40+ foot dock and the water is about 6 feet deep, and she said we could put it there) We have a plan, but we need to know what works the best to slide on? We were thinkin carpet and soap? or does anyone know anything about the stuff they use on professional water ramps? I think its called andendex or somethin like that. Any ideas would be great. thanks


T-lo