Bath time hard?


We have an almost 6 month old and he is out of control in the bath! He loves it and splashes like most kids but he is arching his back and either coming out of the baby bath tub (by his head) or if we sit home up he arches his back and falls back. So we need 4 hands on deck at all times. We have bought 5 different tubs with no luck. Right now we are in the rubber ducky tub but he’s so long it he seems crammed. Any recommendations??