Story with Island of Screams where blood used to get iron?

[Threedoor]

I read this in the 80's I think. It was people living on a water planet with Islands they lived on. There were normal respectable professions that had names like criminal professions. The one that sticks in my mind is "Hoodwink".

I also remember them figuring out that they could get metal in the form of Iron by smelting it out of their own blood on an Island called "the Island of screams" due to their method of getting the blood.

It's driving me nuts trying to find this story!

Thanks,

Keith

[Triffid]

That's "The Blue World" by Jack Vance.

[Threedoor]

That's "The Blue World" by Jack Vance.

Looking at the wiki page 100% confirmed this is the book I was looking for!

Thank you sooo much :)

Keith