some basic yoga inspired stretches also help..
grabbing your hands together over your head and leaning to the left and right to stretch the obliques
grabbing hands behind your back and raising them up together while bending over stretches the front of the chest and shoulders
the baseball stretch with a towel or speargun, grasp the object with your hands more than shoulder width apart and raise your arms up over your head and down behind you (chest and biceps)
and a good reach for your toes and pull back to stretch the ever important hamstrings and calves.
If i spend about 20 minutes doing these stretches before a dive, I dive better and am not sore at all after