I only lack 3 words. I'm sure I've never read this, and anyway, I had to give back my HoMe books (which I only had borrowed) so I can't look it up, even if I knew where...
Our ships go now without the wind,
and many are made of --t-- that s---r-t- hidden ro--s (rooms?)
and they sink not in gale or storm;
but they are no longer fair to look upon.
sounds somehow like Numenoreans...
I just have to keep guessing to find out the material the ships are made of...
How about A ?