Captain Nemo & the terror from 20,000 fathoms (A work in progress)

I thought it was about time that I had some tentacles in my portfolio and as I am going for tentacles I might as well go the whole hog and have the Nautilus as well.
Here is the base sketch for my next poster and tshirt.

Obviously there is still a lot of work to be done but you get the idea. Any feedback will be gratefully received (as long as you say that you love it) :o)