Submarine 
To dream of a submarine suggests that you are discovering your inner spirituality and personality. You are reluctant to express some of your feelings to others. This dream may also be implying that you should approach a situation via an alternate route. If not, then you may want to change your views on an issue. You should carefully assess an issue before making a decision.
Underwater
To dream that you are underwater represents that you are overcome with emotions and need greater organization in your life. You may even be over your head in some circumstances.
To dream that you are breathing underwater signifies a withdrawal back into the womb. You yearn for a chance to return to a position where you were liberated from responsibilities. Maybe you were feeling unable to provide for your own needs and caring about yourself. You may even be inundated in your own sentiments.
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