Peter Chrisp’s great Finnegans Wake blog, From Swerve of Shore to Bend of Bay, reads the last page of FW — ALP’s emptying into the ocean — as a “contemplation of the mystery of death”. No doubt it is that, too. But it is also a contemplation of the mystery of birth, the coming forth by day, as recorded in these comments to PC’s post:

The take here, or takes rather, seem strangely unambiguated. For is this page only Budgen’s “contemplation of the mystery of death”? Or is it not decidedly also “contemplation of the mystery of birth”? Where ALP as the soul must pass away from all the collective possibilities of life, hence all the great and small events of world history that express those possibilities, into the cold light of day as the animation of a particular individual like HCE.
“And the clash of our cries till we spring to be free (…) I am passing out (…) till the near sight of the mere size of him, the moyles and moyles of it, moananoaning, makes me seasilt saltsick and I rush, my only, into your arms. I see them rising! Save me from those therrble prongs! Two more. Onetwo moremens more (…) Carry me along (…) to washup. Yes, tid. There’s where. First. We pass through grass behush the bush to. Whish! A gull. Gulls. Far calls. Coming, far! End here. Us then. Finn, again! Take. Bussofthlee, mememormee! Till thousendsthee. Lps. The keys to. Given! A way a lone a lost a last a loved a long the…”
Is this not the way of the birth canal where a familiar warmth in collective life (or Liffey) must be left behind for isolated individuality: “My leaves have drifted from me. All. But one clings still. I’ll bear it on me. To remind me of. Lff!” What might be called a first gift of life in the collective leaves/lives of the Liffey — relived-relieved-releafed-releaved every night in dream — leads to a second gift, individualized “mememormee”, via the kiss/keys(kees)/buss from the parting portal lips, ἡ πύλη τοῦ οὐρανοῦ. Yes, the cause of death is birth but this is not a linear fate, but one of a “yes tid” where life and death like night and day are primordially caught up in the other in a sort of tide-time, each knotted to the other — Kevin’s “sacrament of baptism or the regeneration of man by water”.