These two books is characterised by the use of symbols {allegoric-paranormal}.
Its understanding must be by the help of the holy spirit. without the endowment of the holy spirit non can understand its meaning and the message therein for us.
Daniel {Dan12:4} was instructed to shut up the words and seal them until time of the end.
ie to say that book of Daniel should be called sealed book at his time. In the other hand the book of revelation elucidates what was shutup inthe book of Daniel as you can see from its name ''revelation''. It gives more light to the sealed book {the book of Daniel]. So the two books had somethings in common.

I'm here to give readers of this books or many that find it difficult to understand the message conveyed by these books {Daniel & Revelation] an insight. There is awaiting promise by God to those that read, listen and practice the message therein {Rev1:3}.

The writers of this books used allegoric paranormal as it was been shown to them God.
Here are the symbols and its meanings as been interpreted by the Bible it self.
The only way to undersstand Bible is by allowing it to interpretes itself.
SYMBOLS AND MEANING:
1:'Water' or 'sea' represent 'Nations of the world' [Rev17:15]
2:'winds' represent 'war' 'strife' 'bloodshed'.[jer25:32-33]
3:'BEAST' represent 'king' 'kingdom' 'Empire' 'seat of power' [Dan7:17,23].
4:'HORN' represent 'seat of power', 'Empire' 'kingdon'{Dan7:17,23}.
Note; this not for ve knwn all but for humble minds in seach of the truth.
For more study check this link; http://www.666man.net/.

I value your effort. But again, one must be careful when interpreting symbols especially in the books of Daniel and Revelations. The symbols used do not always all the time refer to just the same thing - let me show this with the first example you gave:

dreamnaira:

1:'Water' or 'sea' represent 'Nations of the world' [Rev17:15]

It is not in every case that WATER represents the NATIONS. It is in the context of Rev. 17:15 that "waters" are explained for what they mean -- "The waters which thou sawest, where the LovePeddler sitteth, are peoples, and multitudes, and nations, and tongues".

However, it is clear from other verses in the Revelation that water/waters have different meanings as well:

Rev. 8:11 -- "And the name of the star is called Wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter."

Rev. 11:6 -- "These have power to shut heaven, that it rain not in the days of their prophecy: and have power over waters to turn them to blood, and to smite the earth with all plagues, as often as they will."

The above examples, in whatever way they may be interpreted, do not represent NATIONS.

Another example in Daniel:

dreamnaira:

2:'winds' represent 'war' 'strife' 'bloodshed'.[jer25:32-33]

Not in every case. Consider the following:

Dan. 8:8 -- "Therefore the he goat waxed very great: and when he was strong, the great horn was broken; and for it came up four notable ones toward the four winds of heaven."

What would we understand by the term "four winds of heaven"? Well, consider Jer. 49:36 -- "And upon Elam will I bring the four winds from the four quarters of heaven, and will scatter them toward all those winds; and there shall be no nation whither the outcasts of Elam shall not come."

Would the "four winds of heaven" in all casesin Daniel be considered as war, strife, and bloodshed?