7blades screw for Akula - How large for my scale?

[turbobearcat]

OK here is what I'm trying to do, I bought the Dumas Akula
kit today and seen what kind of work is involved, more than I
thought an any of my ships I have build! So I want to make
this kit as real like as possible, so I'm going to have a 7 bladed screw made for it, however I have no idea what size to have made! If anybody has an idea or Dave you would know, please let me know what size I should use for this kit.
so send me some measurements!
Also..should I use Dumas's WTC or a home made one?
ordering from Subtech the extra control surface and motor w/gearing. ect ect..

Mark..first real LARGE sub for me..

[bigdave]

The prop size I used

The prop size I used is 40 mm. That is what it measured on my plans. I used a 6 blade prop. I could not find a 7 blade in 40 mm. Dave.