This feels like a good dream. I have recently had an awakening of feelings of attraction to other women. Wondering if this dream is connected in some way. Water in dreams nearly always symbolizes emotions and the unconscious. That the water is clear and calm also suggests emotional clarity and peace.
Dolphins are definitely feminine symbols.
And as you say, you are attracted to them. Perhaps you are longing for partners who will nurture your own feminine nature. The discovery of your ability to jump, the happiness you feel, the ease with which you glide across the water - all are pleasant discoveries in the dream. Best of luck exploring your new relationships. In no way are these sites intended to substitute for the professional services of a medical doctor.