If my Bark sink — Roar in Disguise

If my Bark sink ¹
'Tis to another sea－
Mortality's Ground Floor
Is Immortality－

(F.1250/J.1234)

[1] my Bark:: roar in Dickinson's poetry.
[2] another sea:: a vast literary world of her own.
[3] Mortality:: earthly words that live and die. Ground Floor:: basis, foundation.
[4] Immortality:: words that esacpe censorship and live.