Just my opinions on these subs, decided to post them because it doesn't look like you've gotten any other detailed opinions.
Claustvine von Lübeck: Aesthetically, the general design shape is a little odd. It's unique enough to where I wouldn't consider it 'bad', but just a bit strange. You obviously put effort into cleaning up most of the wires, but there are a number that, from the picture, seem to be a little messy. I'd fix these up when you get the chance. Or don't, if it doesn't bother you. I assume the top-left room is the brig, if so, the ladder will be a problem for that, might want to move it. The ammo storage room next to the brig is quite unappealing to look at, and I have to ask why you didn't just make it bigger instead of stacking things ontop of one another. Plus all the other little details, like the railgun controller in the firing room being placed oddly, the dual hulls, etc etc.
Functionality wise, looking at the reactor, where's the storage for fuel rods? Do people have to walk across half the sub just to get wire, a screwdriver and a rod to fix it? Why are there two water-sensors in some of the rooms; Just use relay components if their wiring limit is reached, those playing on lower-end laptops with performance issues will thank you for it. Diving suits are oddly placed, and from the image, is there only one? If there's only one or two players on this sub, won't they have to constantly run across the length of the sub from the bridge to the loading bay? That could prove troublesome.
All in all, I think this needs some work. It's got alot of problems with it's layout. But if you put in some more time, I'ms ure it'd be great.
Bismark von Leipzig: First of all, I really like the layout. The curved edges, the U-shape, it's very nice to look at. Has generally the same problems as your other sub aesthetically, such as wires being messy, things stacking ontop of eachother/floating. Is that the brig at the front with a mini-map in it? Interesting. I wouldn't know for sure without playing on it (which I haven't for either) but the ballasts look like they might fill up rather slowly, they're a bit big with too few pumps. You should also make your light components cast-shadows (I think it's disabled on the ones in the bridge, not 100% sure though) Seems like it'd be hard to fight with, with the small amount of railgun coverage and all (I can only see one, but the ends of the submarine are off the picture) though that may be intentional. Docking would be quite difficult, especially if the main sub is moving, and it'd be completely incompatible with most respawn shuttles. You're also missing a few vents, especially in the smaller rooms like the airlock, the loading bay, top left room, etc. There also seems to be no bilge, just ballast tanks, which is generally fine for smaller subs but I'd say this sub is big enough to warrant one. The spare shells could easily be knocked off. Double lights in the airlock? Too many lights in general, really.
Both subs seem to share design goals similar to that of the swordfish and default subs, which is obviously a choice you've made, I just disagree with it because both submarines are fairly unique, and the shared designs kinda just take away from it and just isn't really intuitive. (It's not a negative for the submarines itself, just to make that clear, 100% my opinion and you can choose to ignore it.)
I think both subs need some refining, particularly the former, but providing you're willing to spend that time I'd say they're pretty good, and I encourage you to make more
