I’m designing a world where fully enclosed vehicles that can handle complete submersion into water are commonplace. While amphibious vehicles exist, a different class of vehicles has been introduced: drivable across the bottom of waterways and natural rivers.
Just like with amphibious vehicles there are limits to how rough the waterways can be, but what I’m interested in is how the vehicle’s wheels/tracks/whatever would be designed to allow decent locomotion across the ground of the waterways, while also providing a good locomotion when on land.
Things that the vehicle should be able to perform:
- it needs to be fully submerged and deep enough not to bother regular boats floating on top. No floating on the surface!*
- It needs to be able to drive extended distances up or downstream, as well as just crossing the river.
- It needs to be able to drive on roads and cross-country
- It needs to be able to enter and exit water at places where a regular amphibious vehicle would be able to enter and exit.
- It needs to be able to handle most surfaces of rivers, like mud and rocky ground.
- The aim is around
305km/h speeds when submerged. 12050km/h on roads.
- Having different modes of locomotion in water and land is allowed as long as its not mutually exclusive.
The question: what type of locomotion would fit the best to achieve these goals?
Note: I am not asking for what you might think is more efficient. That is why I already recognize the option for regular amphibious transport modes. Tracks for vehicles is also an incredibly inefficient mode of locomotion compared to wheels but its designed for specific situations. That is what I am asking here: a mode of transport for this specific situation.
You can pick the type of vehicle yourself (personal car, small truck, big truck, full blown tank), but if you really feel the need to be stuck on one specific design:
- 15 tons in weight
- 7m in length
- 3m in width
- 2m in height (removed to focus on the locomotion rather than questions on the vehicle. Pick a density and dimensions for the vehicle that suits the locomotion you propose.)
*for those that spot the option, having it float at a specific depth and use jets to move as a mini sub is possible, but would still require you to figure out how fast the vehicle would sink to that depth, if it sinks too slow you reach the other side before you reach the desired depth. Also it still needs to drive the parts that aren’t deep enough when it enters the water.