Dreams about flying often symbolize freedom, aspiration, or a desire to escape from your current situation. The beach can represent a transitional space between different states of being, while being underwater might indicate feelings of being overwhelmed or submerged by emotions.

In your dream, the shift from flying over the beach to suddenly being underwater could reflect a contrast between your aspirations or desires for freedom and the stress or anxiety you're currently experiencing. It may suggest that while you seek liberation or a break from your stressors, you feel as though you are being pulled down by them.

Consider reflecting on what in your waking life might be causing you stress and how you can address or manage those feelings. It could be beneficial to find ways to bring more balance into your life, allowing yourself moments of freedom and relaxation amidst any challenges you are facing.