The sea symbolizes life and spirituality in dreams, except when dirty or polluted, in which case it symbolizes your circulatory system.
Drowning at sea indicates that you feel completely overwhelmed with life right now. There is so much going on that you feel like you are going under. The rest of the dream has symbols for why this is how you feel, and this should give clues as to what you need to do to overcome it.
Rescuing someone lost at sea indicates you have a special spiritual ability. When people die, we often assume that the transition to the spirit world is a straight forward process that happens automatically. This is not always the case. Souls have to traverse the astral plane to get to where they need to be. However, the astral plane is vast and souls often get lost in a state of confusion there. When you sleep, and your soul leaves your body, you also visit the astral plane. Your special ability is to find souls lost on this plane and help them to the other side. How you have this ability is irrelevant. It is important that you do not refuse to rescue people in your dreams as this indicates reluctance on your part to using your gift. While you are not immediately rewarded physically for doing this, your actions do lead to positive karma.
