A life jacket keeps you afloat in water in order to save your life. Water is a symbol of emotions, and needing a life jacket in a body of water implies that an overwhelming amount of feelings is causing you great fear and / or discomfort.
The life jacket is therefore a symbol of your ability to surrender and not allow the overwhelm you are experiencing to do any damage.
If you dream of a life jacket, you are connecting to whatever will keep you safe while you ride out some difficult emotional experience.
If someone in your dream is wearing a life jacket, consider what that person represents as a character aspect of yourself, as that may be the quality that is needed right now to keep yourself afloat.
[1]To dream that you are wearing a life jacket symbolizes that you are in need of some support and reassurance.
To dream that you are not wearing a life jacket when you should be, indicates that you want to approach your problems and feelings head on, despite the notion that it may be painful or uncomfortable.
[2]1. Feelings of security, personal safety.
2. Confidence in conflicts and confrontations.
[3]