You usually see them in diving competitions. The water spouting into the pool gives the divers perspective on the distance to the surface of the pool.
The small pool is a hot tub; divers go in to keep their muscles loose.
Aside from staying in a routine if you watch some of the female divers, they leave the diving pool covering their breasts to prevent showing their nipples which harden in the diving pool. They will recheck their look after warming themselves in the hot tub.-
the waves/ripples created by divers are dispersed more evenly in a larger pool vs. a smaller pool which makes splash from the actual dive and ricochet from the sides more difficult to differentiate
1 diving board and8 diving blocks!
Swimming races and diving
to col off
Divers don't make a big splash when diving into a pool because of the way they have their bodies straightened out. It's the difference between throwing a rock into water, vs. throwing a small stick into the water.