The Undying Lands, for all intents and purposes in middle earth, is heaven, the afterlife for elves. Tolkien established that when an elf or man dies, his soul goes to dwell in the Halls of Mandos, located in Valinor, or the Undying Lands. Elves, because they do not die of old age, can travel to the undying lands by boat, sailing west over the sea (this only works for elves, men would just turn up on the east side of Middle Earth if they tried it).
“Across the sea
a pale moon rises….
A light on the water.”
The moon and light could be interpreted in terms of western cultural beliefs about death. Reports from people who have had near death experiences often describe a “tunnel” and a “light.” The light of the moon and the reflection of the light is like walking towards the light.
In The Lord of the Rings, the forces of evil are referred to as “Dark” and the forces of good are referred to as “Light.” I have also compared light and dark to life and death in my previous posts. In keeping with the light equals life and good while dark equals death and evil theme, the grey ships represent the neutrality of death.
“Why do the white gulls call?”
Elves are called to make the journey to the Undying Lands by the Sea Longing. Sea Longing is an irresistible urge to depart Middle Earth in favor of the Undying Lands and is irresistible and has been described as “perilous” to awaken. In most elves the Sea Longing is stirred by a visit to the sea shore; but in some, hearing the sea gulls is enough for the Sea Longing to take root.
“Grey ships pass
Into the West.”
There are many images of darkness and light in this song and grey is a bit of both: it could be darkness encroaching on light, a little light chasing away the darkness, both in some cases, or either in any other case. Like the “the glass is either half empty or half full” analogy: some people see death as a an inevitability and just accept it; others see death as a bad thing which must be avoided at all costs; and to others death is a good thing and should be embraced as another aspect of life, like childhood and adulthood, another level in the progression of their existence.