Mums who have water birthed & dry birth

Hey mummas. I have a girlfriend who just had a water birth and she was saying compared to her dry birth with her first bub they made her do little small pushes instead of big ones she did with her first bubs. Now I'm not sure if this is because they didn't want her to tear or is it a different birthing method in water to a bed birth? I'm due in 10 days and am interested in a water birth but am worried I won't know how to control myself if I have to hold back a little bit in the water because I haven't experienced birth before. Please advice needed :)