For DD3, my cx seemed effective for a while and for about 20 mins (right before her head was emerging) I needed to vocalise through them. Also felt the need to be on the fit ball. I couldn't lie down through them. They were painful enough, but I expected stronger considering it was active labour.

With DD2 I was in the water and the cx 'bit' a lot less, but followed the normal pattern - lasting longer, closer together.