Swimming in a dream tends to reflect how you're handling your emotions in the moment -- moving through them with ease, or struggling against a current that feels stronger than you are. Smooth, confident strokes can point to emotional adaptability, while fighting the water often names feelings you haven't yet learned to move with.
Jupiter conflicts with those who are ruled by Mars, and Mars conflicts with those ruled by Jupiter. - Picatrix (Andalusia, ~1000.AD)