Hi, I live in Puerto Vallarta, if your looking for specific info on temp, vis and other things drop me a line i will help you out. I just joined this site, Vallarta has great diving. there is alot of life at all the dive spots. sometimes the visability is not the best, but if you go slow and look around you can see many things.all the dive sites are a little different. which is nice for the diversity. los arcos has a wall dive that is nice , drops down 1600 feet. also in the shallows of christ , is a nice small reef that varies from 30 feet to 80 feet. usually alot of night dives is done there. marietas is volcanic in nature. has some nice swimm thrus. some at 30 feet and another area has some at 50 feet. i see alot of diversity of sea life there cause there is a reef that jets out from the island and then there is lot of sand , so you get sand life (guitar fish, one sided fish, stingrays) and reef life( sea horse,turtles mantas,fish. chimo is beautiful, there are alot of different dive sites in that area. one in particular is so big that you do one dive one direction ,second dive the other direction. one side seems to go down forever and you feel the depth, and you go the opposite direction and stay 60 feet with lots of beatiful rock formations and abundance of fish octopus and sea life. thats just one of the spots in chimo. el morro is also an advanced dive, just outside the bay. there is a tunel that opens up at about a hundred feet, huge entrance then you follow your way and exit out about 60 feet. great moray eels inthere, enveloped by shrimp all around them. about the mantas. spring time is there mating season here in vallarta. so there are lots of mantas. you can see mantas almost all year round at chimo and el morro. but when they mate you can usually get a chance to see them at any dive locaiton, even los arcos. if you want more specific informaiton send me a message.