Harbour Height 1st edit

[Richard]

Hey Carl,
Welcome to the site

I like what you're going for here. However, I do have some thoughts:

Harbour Height -I feel like you should name this "Harbour Night" just because there is a slight sense of menace here that would support starting with a night image. Plus, your poem establishes the height aspect, so you don't need to say it outright.


 
Through another window, the maritime -Why "another" window? There was no mention of a first window, so maybe change to "my" or "our".
marina is decked out in miniature -I like the alliteration between this and the last line. I like the enjambment between "maritime" and "marina" because it emphasizes the sense of isolation in this poem.
 
where people hurry across the swing
bridge in ones or twos before amber -This stanza gets you where you need to go, but could use something to spice it up. Maybe a metaphor, or some other literary device.
 
warning-lights flash in the half-dark.
I can’t make out faces this high -I like the idea behind this line. I just wonder if you would consider exploring it more. What do the faces look like, even though the speaker can't identify who they belong to?
 
just the purpose in their walk
passing blurred berths of tugboats -Again, nice alliteration here. The way you go into detail for the tugboats is how much detail you should go into when it comes to the faces in the last stanza.
 
that look like interlocking plastic -This simile works for me because I can see what you mean in my mind.
building-blocks, as if wind-beaten
 
walkways hereabout don’t lack railings.
Except one guy, who has stopped -I don't know if "Except" is the right word here. Maybe something like: "Then one guy..." or "Unexpectedly, one guy..."
 
or merely paused, and shakes my hand -To me, this is the payoff for the poem, so it needs to be stronger. I sort of get what you mean here, but you need to play with the image more. Maybe something involving relating their eyes to shaking hands. This is just too abrupt to work on its own as an image. You need to expand on it. 
seeing me watching from the 27th floor.

Overall, I think you have a good first draft here, and I look forward to seeing where you take this from here.

Thanks for the read,
Richard