Most students who approach the book of Revelation from the normal or literal method of interpretation understand the words following the statement about the new heaven and new earth, “and there is no longer any sea” to simply mean that because of the changes in atmospheric and human conditions will be so different water as we know it today will not be needed. The term “sea” is the Greek “thalassa” which is used of all forms of water—the oceans, lakes, etc. There will be a river of water (22:1f) that flows through the New Jerusalem, but this is the only other source of water that is mentioned. This may be because there is some kind of relationship between God’s judgment on demon spirits and the oceans. This may be (note I said, “may be”) indicated by a couple of things:
There is an interesting statement made in Luke. 11:24. Here we read that the “when the unclean spirit goes out of a man, it passes through waterless or arid places seeking rest,…” It appears from this passage that demons travel seeking to habitat waterless places. It appears they seek to avoid water. Further, in Luke 8:30-33 we have an interesting occurrence. Speaking to the demon-possessed man:
8:30 Jesus then asked him, “What’s your name?” He said, “Legion,” because many demons had entered him. 8:31 And they began to beg him not to order them to depart into the abyss. 8:32 Now a large herd of pigs was feeding there on the hillside; and the demons begged Jesus to let them go into them. So he gave them permission. 8:33 Then the demons came out of the man and went into the pigs, and the herd of pigs rushed down the steep slope into the lake and were drowned.
Finally, the judgment God used on the antediluvian world (which was was somehow involved in the sin of a portion of the fallen angels) was water with the earth’s crust breaking up to flood it along with the rain. All of this could indicate a relationship between water—the oceans, or the subterranean levels—and the abyss where certain demons are confined. The swine running into the water—was certainly a judgment—and probably symbolical of Christ casting them into the abyss which is what they did not want. This could be part of the reason for the absence of the oceans in the new heavens and earth. For more on the sin of Genesis 6 and the sons of God (which I believe were fallen angels) see Bob Deffinbaugh’s series on Genesis on our web site.