Sometimes i go fishing in my small boat, I'm wondering if i get thirsty should i drink a small cup of sea water, can it make me feel better?
Drinking sea water actually makes you more dehydrated. This is because your kidneys have to process the salt water and will use existing water in your body to dilute the salt water.
Simply having a single glasses of seawater isn't going to kill you. But it is not good for you.
In a survival situation, drinking seawater will end up killing you.
However you can extend your freshwater rations by cutting it with seawater, mixing 1 gal of seawater for every 4 gal of freshwater. For example, if you had a 5 gallon container of fresh water… refilling it with saltwater after drinking 1 gallon of freshwater from it, will end up giving your 6 total gallons of usable water. The 1:4 ratio of salt/fresh water is still dilute enough to not cause harm.
salt absorbs moisture despite it being from the ocean already in water. The salt, once your body digests it, will actually make you more thirsty. so it is technically not a good idea to drink sea water.
Yes it's very good for you actually. The salt in the sea water is alkaline, and thus, acts as a detergent to bugs and bacteria. I always drink a small glass a day.
Between the two of them, Fuzzy and Efflandt have pretty much nailed it for you here. I only add the following part of the account from Thor Heyerdahl, of the voyage of the Kon-Tiki, in support of the point made by CG-23 Sailor, and for your own and general interest:
"When tormented by thirst in a hot climate, one generally assumes that the body needs water, and this may often lead to immoderate inroads on the water ration without any benefit whatever. On really hot days in the tropics you can pour tepid water down your throat till you taste it at the back of your mouth, and you are just as thirsty. It is not liquid the body needs then, but, curiously enough, salt. The special rations we had on board included salt tablets to be taken regularly on particularly hot days, because perspiration drains the body of salt. We experienced days like this when the wind had died away and the sun blazed down on the raft without mercy. Our water ration could be ladled into us till it squelched in our stomachs, but our throats malignantly demanded much more. On such days we added from 20 to 40 per cent of bitter, salt sea water to our fresh-water ration and found, to our surprise, that this brackish water quenched our thirst. We had the taste of sea water in our mouths for a long time afterward but never felt unwell, and moreover we had our water ration considerably increased." ¹
¹ Kon-Tiki Across the Pacific by Raft by Thor Heyerdahl.
The concentration of salt in seawater is way too high. The excessive salt in the seawater actually pulls water from your body in an attempt to dilute the salt leaving you thirstier. Drinking a lot of it will cause kidney damage & death.
Real seafarers will laugh at you and call you derogatory names.
You can drink about 1oz. Or 1 shotglass a day. Cut 1/2 & 1/2 with sea water. To replace salts you loose in the S Pacific. Keeps you from sweating as much in the tropical sun. Or 1/2 oz. a day of sea water. In high heat day's.
Drinking too much is bad for you. Human kidneys can not flush out that much salt in your urine making you urine more, leading to dehydration
Nope, the salt content will make you dehydrate. It is the worst thing to do if you are thirsty. Make sure you take fresh water with you.