What books that? And I loved the look of the Sea Shadow, a useful tesbed for sure.
Skunk Works by Ben Rich and Leo Janos
as it turned out, Sea Shadow was a bit too stealthy.. it generated a return smaller than that of the noise from the waves on the surface, so a radar set properly would be able to find it as an empty point in the noise.
Even before I saw NightLord's comment, something smelled fishy about that. By the time you scale it up, and add all the kibble associated with a serving warship, that problem would go away.
This, Sea Shadow was purely R&D, I'm going to guess that she didn't have a lot of space and weight capacity for weaponry, and was too slow for anything the USN really wanted her for. Not to mention that she was likely quite observable on sonar, which is much harder to hide from than radar.
The diesel engines were up in the main body, and the pontoons had electric motors. Not saying that turns this thing into the Red October, but I have to imagine there are worse starting points.
I'd also suggest that with her superstructure shape means she's going to dig that bow into a serious wave pretty damn hard. Buoyancy will try to push it upwards, while the shape going through the water is going to push it down, and I can't imagine something slapped together as a rough prototype is built for that kind of impact and stress. She'd turn into a stealth submarine pretty quick, I fear.
Stealth shapes and ship shapes seem even more incompatible than stealth shapes and airplanes! I've dug no deeper than wiki, but the Tumblehome hull of the Zumwalt has some stability issues.