To dream of a sea horse signifies the strength of your instinct and intuition. It may also symbolize a change in perception or attitude.
If the sea horse is invisible, then it indicates that you need to face your personal concerns rather than trying to evade them. Perhaps you need to adopt a fresh approach to a situation.
[1]1. Hope that something magical and miraculous will come into one’s life to solve a major crisis.
2. New approach to life.
3. Something playful, whimsical and strange.
4. Grace.
[2]