a. In the lines 64-66 of "The Seafarer", the author speaks of the joys of God fervent with life, where life fades into the earth. Maybe he is talking about the ephemeral of life.
b. The opening section talks about being swept back and forward by the sea, of all the pain and sorrow he has found in a lifetime of sailing. But, somehow, he has survived and wouldn't change what he does. "And how my heart/ Would begin to beat, knowing once more/ The salt waves tossing and the towering sea!" Here he talks about being unable to wait to get back to the sea, despite all the pain he has found. Life might be short and quick, but what a life is the one in the ocean.