Bring Back The Proteus Submarine.

The only changes of original design I would think good would be:

1) Add specimen manipulator arms to allow picking up and moving small objects underwater. But as these would be detracting from the Proteus sleek design, I would make them retractable into the ship hull.

2) Replace the simple 3 telescoping support legs with 3 or 4 track-based drive modules that also retract within the bottom hull when not in use. These to provide an amphibous function to the Proteus to allow it to drive into and out of the seas it could explore. Such electric motor driven tracks would be slow movement, but this is only for short distances.

3) The computer revolution that has occured since "Fantastic Voyage" has obsoleted paper charts. So the forward chart bin should be removed. This would then provide space for the remote controls of the new manipulator arms mentioned above.

4) Beneith the forward viewport there should be at least a sonar display unit. Possibly additional, but small, data display devices there also.

5) I would replace the wireless radio with a computer-based comunications system.

6) I would replace the larger (gaudy looking) mechanical-dial guages with 1.5" tall 7-segment LED digital numeric displays, and of various colors per display. I know that 7-segment LED sdisplays are not 'state-of-the-art' now, but they are more advanced that the mechanical-based guages, and I think they were (and are) cool looking. I know a single computer screen can display it all. But that alone does not retain the visual appeal of the past. Also, it does not hurt to have backup display devices (as well as systems). And in that reguard, I would still keep a few smaller-sized mechanical-dial guages. Might even throw in a few of those non-descript beautiful 2" colored blinky lamp indicators. ;-)

7) I think I would do away with the snorkel tube. Aside from passing a nearby giant lung, I cant see how that device could be of much use.

8) A pop-up radar scanning antenna might be useful when the ship is surfaced.

9) Add a remote controlled drone camera with lights to see into small tight locations.

10) And a ship's central computer system with a hands-free voice-interactive virtual personality would add many functions and another character to the mix.

11) I would not limit it's atomic power to minutes. It should last for months or years on an atomic fule load.

I would not try to 'weaponize' it. It is a short-range 'research' vessel.

Those are the only changes I can see needed. Otherwise, I would keep the rest in it's well-designed original state.