have trouble living with MK, Wario, Snake, Bowser, DK, Marth, and G&W.
You shouldn't be having trouble recovering with any of these characters, save maybe bowser because he's so heavy, or marth because of his almost purely vertical recovery. MK has a hundred million jumps to help you get out of the water, plus his up-b can sweetspot a ledge at any point during the animation, so if you use it even under the stage you'll probably still survive anyway. Wario has his bike which will send you back upstream while letting you jump off it with enormous vertical lift, snake's third jump lasts forever and you can negotiate which direction it goes during the jump. DK's third jump stops all his aerial momentum and lasts a long time with excellent horizontal recovery value which can save you from even the furthest left edge of the stage. G&W's third jump is amazing in so many ways on this level (It's one of his best due to the high ceiling and short sides). If used ANYWHERE besides below the actual platforms of the stage you will ALWAYS live because of the parachute you get from it.
The best advice I can give you (this is my third favorite level and I have no problems recovering on it unless I'm at the extreme left edge in the water) is to time your recovery so that you shoot up through that little space between the left platform and the center area of the stage. The worst thing you can do is try to recover while you're under any of the stage's platforms since you can't go through them.
I personally believe the only times you should die to this level are when you fall in the river too far to the left, or you get hit by a klaptrap. You just have to be patient and not have the mindset that every time you fall in the water you're going to die. Just wait and time your jumps so that you come out of the water somewhere you can still hit a ledge
today something really wierd happened. i got double spiked by a claptrap within a second; like one spiked me on 0% and i didn't die then a split second later another one spiked me and killed me :o it was possibly the same one.
It was the same one. A klaptrap cycles through the stage every 10 seconds (though there's a slight deviation after about 5 minutes, nothing too major). It will appear between the right and center platforms every time the clock reads x:x7 and between the left and center platforms every time it reads x:x5. What probably happened was you got hit by the first one, didn't die and came up to the left because of the current, and it hit you again as it was jumping out of the water again. The best way to avoid this happening is to DI the klaptrap hits right and up. This'll help you survive at lower percents and make sure you don't get hit by the second one (if it applies).
Hope my advice helps.