Modern survival guides consistently advice against drinking sea water.
Speaking of Alain Bombard. The most likely explanation here is that he consumed enough FRESH water (with fish and rain water) to dilute sea water he drank to safe levels for his body.
So if you are on a boat in the middle of the sea NEVER drink sea water. This can save your life.
If you're in an area where you're perspiring a lot, then occasionally drinking sea water would actually be beneficial as there aren't many readily available sources of salt.
I work construction, in the longest heatwave of the summer I was putting tablespoons of salt into my water jug as it's quite easy to become nauseous when drinking a gallon of water inside a work day. Not to mention you don't want to get disorientated or light headed whilst 30ft in the air.
Long time survival in a hot environment requires a source of both fresh water and salt. The ocean is a far easier source of salt than searching for anything in nature.
I buy these 100 at a time - seems to do the job pretty well.