>Surplus real subs weren’t cheap enough or pristine enough to use as instrumented targets, so the Long Beach Naval Shipyard built three identical 4/5-scale sub

>Surplus real subs weren’t cheap enough or pristine enough to use as instrumented targets, so the Long Beach Naval Shipyard built three identical 4/5-scale sub hulls to hold instruments while submerged. This seems incredibly scant by today's U.S. Military standards. Why not build the sub hulls exactly to scale? Hell, why not build real submarines to perform the test on?