What I wanted to share was my theory about the title. As has been frequently remarked, drowning is not mentioned in the lyrics, although there is a quick nod to ocean imagery ("tides and storms.") (Incidentally, this piece looking at the history of water and drowning images in U2 is worth a read if you've never thought about how often such allusions turn up -- and I think they have different resonances in different places. Here I'm only considering the narrow question of this one song's name.)
Until "Unknown Caller," "Drowning Man" had the distinction of being the only U2 song which majored on lyrics obviously intended as the voice of God - who, however, quotes Isaiah along the way. It pictures an earnest Lover reaching out and appealing "take my hand," promising acceptance, steadiness, strength -- "if you can" bring yourself to accept the help and "hold on tightly." But again: why reference someone who is "drowning" for that appeal? Couldn't it apply to any addressee in any situation?
Well, here's what often seems plausible to me. I wager that the choice of a "drowning man" to characterize the addressee of the song may actually be a literary allusion. I would not be surprised to learn that this title draws on a striking and memorable image of the need to surrender completely to grace found in The Normal Christian Life, the best known work of early-U2-influence Watchman Nee:
When you are reduced to utter weakness and are persuaded that you can do nothing whatever, then God will do everything. We all need to come to the point where we say: 'Lord, I am unable to do anything for Thee, but I trust Thee to do everything in me.'
I was once staying in a place in China with some twenty other brothers. There was inadequate provision for bathing in the home where we stayed, so we went for a daily plunge in the river. On one occasion a brother had cramp in one leg, and I suddenly saw he was sinking fast, so I motioned to another brother, who was an expert swimmer, to hasten to his rescue. But to my astonishment he made no move. So I grew desperate and called out: 'Don't you see the man is drowning?' and the other brothers, about as agitated as I was, shouted vigorously too. But our good swimmer still did not move. Calm and collected, he remained just where he was, apparently postponing the unwelcome task. Meantime the voice of the poor drowning brother grew fainter and his efforts feebler. In my heart I said: 'I hate that man! Think of his letting a brother drown before his very eyes and not going to the rescue!'
But when the man was actually sinking, with a few swift strokes the swimmer was at his side, and both were safely ashore. When I got an opportunity I aired my views. 'I have never seen any Christian who loved his life quite as much as you do', I said. 'Think of the distress you would have saved that brother if you had considered yourself a little less and him a little more.' But the swimmer knew his business better than I did. 'Had I gone earlier', he said, 'he would have clutched me so fast that both of us would have gone under. A drowning man cannot be saved until he is utterly exhausted and ceases to make the slightest effort to save himself.'