The cost is actually much lower than you would think. Several years ago, I began conducting feasibility studies on the cost to build a full-scale replica of a Typ XXIII u-boat, via a non-profit organization dedicated to the project based on historical interest.

The XXIII was chosen for several reasons. First it is smaller (by 1800 feet) than a Typ VII, it requires only one engine and doesn't require an ornamental deck gun to look authentic.

Our advances in engine design, electric motors, batteries and low power consuming LED lighting all contribute to lower production costs. Additionally, by using more modern ballast tank and steering controls, not only could costs be reduced, but the replica's methodology of operation could be condensed and simified.

Air intakes, exhaust vents and other crew-serviced pre-diving operations could be simplified with pneumatic controls from one station. My emphasis was to sit k with pnuematic and hydraulic controls to eliminate building a highly complex computer operated machine.

This is a concept that I have never stopped working on...