"The sea is no more" means that the unbelieving world will no longer exist, all people will believe in God and Jesus Christ.
I don't know if you are correct or not, but there appears to be numerous people who take the sea in the literal sense, that it means a literal body of water. Except some of what is recorded in Ezekiel 47 contradicts that. There is still a sea per Ezekiel 47 and that Ezekiel 47 is obviously involving the same age and the same things Revelation 22:1-2, for example, are involving.
After all, there can only be one endless age not 2 endless ages. The latter makes zero sense and everyone knows it. Clearly, Ezekiel 47:12 is involving an endless age, as is Revelation 21-22 as well.
Ezekiel 47:8 Then said he unto me, These waters issue out toward the east country, and go down into the desert, and go into the sea: which being brought forth into the sea, the waters shall be healed.
If there is no more literal sea as of Revelation 21:1, then why is this verse contradicting that? Verse 8 is involving the same age verse 12 is involving. And verse 12 is involving the same age Revelation 21-22 are involving. Why would the Bible be contradicting itself here, where, in the OT it insists there are still literal seas, but in the NT it insists there are no longer literal seas? The Bible obviously isn't contradicting itself though, therefore, it is one's interpretation giving the false impression the Bible is contradicting itself.
Ezekiel 47:12 And by the river upon the bank thereof, on this side and on that side, shall grow all trees for meat, whose leaf shall not fade, neither shall the fruit thereof be consumed: it shall bring forth new fruit according to his months, because their waters they issued out of the sanctuary: and the fruit thereof shall be for meat, and the leaf thereof for medicine.
Once again, this verse demands that an endless age is in view. How can the fruit thereof never be consumed unless the fruit thereof is endless? If it wasn't endless, obviously it could be consumed eventually. Not to mention, both Ezekiel 47:12 and Revelation 22:1-2 have the following in common as well--- it shall bring forth new fruit according to his months, because their waters they issued out of the sanctuary(Ezekiel 47:12)---and yielded her fruit every month(Revelation 22:2), then Revelation 22:1 meaning the waters and sanctuary meant in Ezekiel 47:12.