Unlike rivers and seas, lakes, lagoons, pools, ponds and puddles are typically still, so if they feature in your dream, they could be reflecting your emotional calm.
If a lagoon appears mysteriously, reminding you that still waters run deep, this could be referring to your own hidden strengths or weaknesses. Some dream researchers believe that lagoons in dreams are symbols of the womb, so perhaps when they appear in a dream, you are longing to retreat to a safe haven.
If you are a woman, they may refer to a desire for children and if you are a man, a longing for intimacy. Dream ponds can also reflect your unconscious personality, facets of which will be represented by the creatures who live in it.
If your dream pond is lifeless and stagnant, is your emotional life currently unfulfilling? If you watched a fish swim to the surface, could it have represented the emergence of your intuition? If the pool suddenly transforms into a whirlpool or maelstrom, this suggests emotional turbulence or confusion in waking life.