The sea in dreams has various interpretations, always depending on the feeling that the presence of the sea leaves us with.
A calm and blue sea signifies an organized and carefree life.
A murky and wavy sea portends a life filled with adventures, hardships, and misfortunes.
If the seabed is clear and transparent, it indicates familial tranquility.
If you see yourself walking on water, be mindful of your behavior, as others are observing you.
If you find yourself alone in the middle of the sea, some inheritance will come your way.
Lastly, the phenomena of tides and whirlpools in dreams are traditionally interpreted as omens of mental distress. However, this also depends on the feeling that each dream evokes.
If you took dives into the sea in your dream, consult the relevant entry on diving.