Balancing containers on a floating plain / cargo ship

Being quite new to the engine, I am seeking helpful ideas how one could do something like that in Unity. Ive played around with joints, tho they look a little "weird". The goal is to have rigid bodies push balanced 2D cargo ship out of balance. First I went with hinge joints, no idea how to edit physics so the water would help balance the ship a little, instead of spinning like a scale. Then tried attaching both ends to a spring joint, looked promising, but no matter how heavy object i placed on there, it stayed balanced...