-When Constantine has to go to the parallel Hell version of Los Angeles he sits in the chair and puts his feet into the... water. He mentions that it eases the transition between the two worlds.
-In order to leave the dimension he had to smash the globe against his heart. It was filled with... water.
-When the second twin sister wanted to gain the powers that she shunned that her dead twin possessed, Constantine put her into the bathtub full of... water. She was held until she drowned, she then came back destroying the bathtub and the water spilled all over the place. The birth/rebirth symbolism is that the water issued forth like when a pregnant woman's "water breaks".
-When the living twin took off her medallion, which served as a "spiritual bullet proof vest" she was dragged through the skylight and then landed in the water and when she was brought out by Gabriel she was to be sacrificed, cut open to allow for the Son of Satan to come through.
-When the movie begins, the main character washes up on the shore. This is the water subliminal to let us know we're in the dream.
-In the beginning when the "kick" to wake one up out of the dream is administered to the main character the chair he's sitting on is pushed backwards and dunked into a tub of water causing him to leave the dream world into the real one. Actually that ends up being a dream as well but you see the use of water as a representation of traveling through or between worlds. Another interesting part was that the bathroom they were in had checkerboard red and white tiles and correct me if I'm wrong, but the Masonic Check in their temples is black and white surrounded by a red border. Its supposed to mean duality, control, and also dimensional travel. It being red and white instead of black and white I supposed represented that they wanted to include the principal elements of black, white, and red, but traded the black for red and only those in the know would understand the minor deviance from the true symbolic representation. A LOT like in Sherlock Holmes.
-When they enter the first level its raining, and one of the crew comments that another of the crew drank too much champagne to explain the rain. Still the water symbolized dimensional travel.
-When DiCaprio and WhatsHerName and Marlo were in DiCaprio's subconscious looking for the Scarecrow/Cappa when it was time to leave the "kick" was the storm. WhatsHerName then threw the Scarecrow off the building into the storm to leave that world. Again water symbolism for dimensional travel.
-When the final "kick" was administered to get the crew out it was the van falling backwards into the river from off the bridge. Again water symbolism for dimensional travel.
There are other movies using water for symbolism of death/rebirth or crossing between worlds. There's the Stargate itself from Stargate. There's Neo waking up in the pod but more importantly sliding down the tunnel and being pulled out of the water up to the Nebuchadnezzar. Ricintoxin81 does a great job of pointing out some examples in his latest documentary lluminati Hollywood Insiders: Beneath the Surface 1 of 8 HD .
Also, it just now occurred to me that in the very beginning of Constantine we see during the exorcism that the only time we actually saw the demon was by looking at it through the mirror. It just now reminded me of scrying and also a video in the The Industry series that spoke of communicating with demons/negative spiritual beings. It showed in two music videos. One was with Beyonce and the other I think was with Ludaris. I could be wrong about the latter but I'm sure on the former. Anyway...
If you have anything to add or correct, lemme know. It only helps out everyone. I've got a channel on YouTube as well. http://www.youtube.com/user/4thKrypton and on there I've got about 15 or so lectures on occult symbolism. Just look up Occult Symbolism 101 all the way through Occult Symbolism 116.
Thanks for your time.