Bathtime = Stress

I am trying to get Ryan to post a video of Aidan in the tub. He is a WILD man. He is so hard to control. It makes bathtime stressful. We have a sling type seat for him and he wants nothing to do with it. If we lay him in it, he rolls and twists off the side. Or he tries really hard to sit up. Once he sits up, he tries to stand. It is hard to imagine this. He is so slippery and so squirmy, that it is getting dangerous. He pretty much squeals with delight the entire time in the tub. I guess he is just so happy that he can't control himself. What kind of a toddler are we going to have here? Any suggestions about how to keep him safe and contained???