It appears to be about a man who has lost his love. He misses her. He would love to have what was. The attachment or need for the both of the them to remain together is dissipating over time. As the saying goes time heals all wounds and out of sight out of mind. He recognizes the passion is weakening i.e. drifting away. His head above the water is what is left of the attachment. He is drifting away into the past. Eventually to drown away or be forgotten.
It appears to be about a man who has lost his love. He misses her. He would love to have what was. The attachment or need for the both of the them to remain together is dissipating over time. As the saying goes time heals all wounds and out of sight out of mind. He recognizes the passion is weakening i.e. drifting away. His head above the water is what is left of the attachment. He is drifting away into the past. Eventually to drown away or be forgotten.