Question: Is Revelations 21:1 stating that there will be no water in the new Earth?
First, although the sceptics don’t like to think or accept that Christ Jesus upholds all things at present in the physical world, Scripture (the Bible) states that as fact (Heb. 1:2–3).
Jesus is doing this to all Creation, as all power and authority have been given to Him until He hands back the finished work to the Father (1Cor. 15:24–25); which is at the end of the “Millennial Reign”.
So; that means that during the Millennial there will be sea, as at present physical life is maintained by water.
At the beginning of the Bible’s message to humans, God makes a firm promise that:
“Whilst the Earth remains, Seedtime and harvest, Cold and heat, Winter and Summer, And day and night, Shall not cease” (Gen. 8:22).
So; that means that up to the end of Millennial the Earth will be similarly maintained by Christ Jesus, but when He returns the Power and Authority vested in Him by the Father, Rev. Chp. 21 transpires, and as seen in Rev. 22:3, there “no more curse” !
This means that all Satan started in Eden has been defeated and all the pain summarised in Chp. 21 is no more!
The conclusion of all this is that the “new Heaven and a new Earth” quoted in 21:1, and “no more sea” are part of a totally new condition, with Satan destroyed (Rev. 20: 7-10), not requiring the current maintenance factors for life as we understand it!