Hm...I'm not sure what it is, but there's something about the whole piece that makes it seem like it's meant to be put to music. I do really like all the imagery, especially the second stanza, and the repetition makes it sounds more chant-like, which is appropriate. The whole sentiment is nice, also. Overall, pretty dang good job. Make up some music, and it'll be downright beautiful. :)

ohh...i really love the idea of the sirens...this poem has the great thought and rhymes...i love it...good job...but here...you described the siren's image...according to myhtology, no one has ever seen the sirens for no one has ever came back...they have died hearing the siren's song...well just to inform you...and i also have wrote a poem about sirens...so pls...if you have the time...pls review it...