What does this idiom mean?

All comments here seem helpful. I might add that it can now be used idiomatically, as an allusion to the original text. That is, I could use it as a metaphor for a non-water-related circumstance in my life. One might be surrounded by opportunities to gamble in Las Vegas, but if one is without money, this phrase would be apt. Or the man who is happily married might be surrounded by beautiful temptresses, but unwilling to be tempted.

This is not an idiom, but a line from Rime of The Ancient Mariner, a poem by Samuel Taylor Coleridge. It means the ocean was all around, but there was no drinking water.

It's not really an idiom but more of an aphorism. It means that sometimes one can be surrounded by something that one cannot use. A person cannot drink sea water. So if you are at a restaurant where they serve only meat, and you are a vegetarian, you could use this aphorism.

It is a quotation from a poem, rather than an "idiom".

The context in the poem is a sailing ship which has been sitting motionless for many days in the middle of the ocean with no wind to move it, thus everyone is very thirsty from excessive sun, and the ship's water barrels are empty. Thus there is no drinking water, though the ship is surrounded by miles and miles of (undrinkable) sea water. Drinking sea water leads to death, because of the salt in the sea water.

Not idiom.

Out in the ocean, you see nothing but water, but you can't drink any because it's salt 瓦特而，

Wasn't this a passage in a book? Men stranded at sea and dying of thirst, since sea water only made it worse? Thus, they were surrounded by water and couldn't drink it.

Coleridge actually wrote: "Water, water, everywhere / Nor any drop to drink."

It is from a poem and describes being on the ocean without any freshwater to drink.

In a liferaft at sea.

http://dictionary.reference.com/browse/water--wate...

http://www.usingenglish.com/reference/idioms/water...

http://www.phrases.org.uk/bulletin_board/6/message...

http://www.huffingtonpost.com/entry/water-water-ev...