The vision describes God's creation of a new heaven and earth (compare Genesis 1:1 with Isaiah 65:17; 66:22). The old creation has vanished because it was subject to decay (see Romans 8:20–21; 2 Peter 3:7, 10).
the sea was no more: The sea symbolized chaos or the abyss (see study note on Revelation 9:1–12) and was sometimes depicted as a roaring monster (see Psalms 46:3; 74:14; see also Job 3:8; 41:1–34; Luke 21:25). The new creation will be free from all such evil.