I'm not sure if you're kidding or not but naval vessels have desalination stations aboard. That's the water they use... they don't bucket it up from the ocean. Hahaha!
If you take in an over-abundance of seawater... you are, for sure, going to die... most likely due to acute renal failure, if you're lucky. Even in moderate amounts - this assumes that you have fresh water to counter/dilute any salt water intake - your brain will be adversely affected. That alone could cause long lasting cognitive disability, loss of motor function or straight up death.
https://www.usgs.gov/special-topic/water-science-school/science/water-qa-why-cant-people-drink-seawater?qt-science_center_objects=0#qt-science_center_objects