Dex's column on drinking seawater


I watched the Discovery Channel last night and they had a show about the sinking of the USS Indianapolis. In a nutshell, they were on a secret mission to deliver parts for the bomb to be dropped on Hiroshima, they were hit by two torpedoes, and the ship sunk in shark-infested waters about 12 minutes later.

When they didn’t show up in port no one thought anything of it, so these poor boys (average age, 19) floundered in the Pacific Ocean for four days and five nights, freezing at night and baking during the day, no food, no water, before a passing plane spotted them. Of course, some of them, in desperation, drank seawater and died.

According to **Dex’**s column, drinking seawater is a definite no-no. I was wondering if this means it’s never a good idea, or if you’re dehyrdrated? If the boys had sipped a bit of seawater now and then before they got dehydrated, could their bodies have handled it better?

1196 sailors. Only 317 survived. :frowning:

Sea water has a salt concentration of about 30g/l, your body fluids have a salt concentration of about 9g/l. Getting dehydrated means that you have too little water in your body fluids, or too much salt for the amount of water. Drinking water that contains about three times as high a salt concentration than your body fluids are supposed to have clearly makes the situation much worse.


Let’s all drink to the moving of this thread to Comments on Staff Reports


Here’s a recent discussion of the topic:

I’ve heard that seawater can be ‘ingested’ anally without problem, because the intestine only absorbs the water, and not the salt.

Enema Survival, hmmm…that would not be a prime time show.

I would like to see how a sailor hanging onto a life raft is supposed to handle this!

Regarding the sinking of the Indianapolis…I’m getting two different stories about why they weren’t missed. According to Wiki, it’s because they were on a top secret mission and no one at port was expecting them. According to the Discovery Channel, ships being late was not unheard of during the war so they didn’t worry.

Did no one at port face responibility for not raising the red flag sooner?

So, after a while of doing that, would you end up with an ass full of precipitated salt? Ouch and eww.

I doubt this very much. My guess is that water would be drawn out of the body to dilute the hypertonic solution in the rectum, hastening dehydration.

Absolutely not safe. Although it’s true that water can cross the intestine and salt cannot, the water always flows in the direction of the greater salt concentration. This is how most enemas work, you irrigate the bowel with salty water, the salty water pulls water out of your blood and into your bowel, and the (hopefully) rehydrated feces are excreted with a net loss of water.

I have read some survival manuals that suggest diluting seawater 1/10 with freshwater (90% fresh, 10% salt) is even better than fresh as you get back needed salts.

Hm, maybe… this would give you about .35% salinity. Theoretically anything less than or equal to .9% should be OK since that’s the salinity of your blood.