Originally Posted by Kenomac
I doesn't seem possible, the rain would agitate the the surface mixing the two solutions. Like you said, I'd have to be pretty thirsty in a life raft and delirious to try it. Sounds like something for "Myth Busters."
While we're on the fresh water topic, do you have plans to add a watermaker
before you head
out cruising full time?
Sounds like something to keep in mind for life raft survival. The mixing could be minimal and with scooping you need only pull off the top fraction of an inch. Also, you do not need pure fresh water in a survival situation, just water with the PSU (salinity) down enough not to kill you or destroy your kidneys. (water intake needs to be less salty than your urine so that you can rid yourself of the excess salt
In terms of mixing we do modeling of the Columbia
River where I work and see the salt
wedge come 20 plus miles up the river with minimal mixing. Of course the fresh water flows out over the ocean for many miles.
Take a look here: Daily Forecasts | Center for Coastal Margin Observation & Prediction
If nothing else you might be able to place a cloth on the surface and soak up some water in a rain.
desperate measures for sure....
Click on the transects to see the salt wedge cross sections along the channel to see the minimal mixing..