waking up.

thinking about tunneling underwater,

and it could use caterpillar tracks on four sides of the cylinder.

like a tank, which can protrude itself to meet the surface of the tunnel,

as it is being dugged inwards.

issue is that the water is in contact with the surfaces, so i dont know

if it will propel forward by a traction system.

Asking GPT, it's actually suggesting to me an idea of a claw-like arms,

but unlikely.

I think my previous designs from long ago is more accurate in this case,

which were protruding 'pads' (as in padding) on four sides of cylinder

to create pressed pressure

so to make it stationary in the tunnel,

and then, the drill protrudes in order to dig.

moving forward can be capterpillar tracks,

which can be another 4 sides of the cylinder.

a propeller mechanism could also work since it is inside the water,

but the contact with dugged ground passing it through it will quickly wear it down.

Protruding rods to penetrate walls of the tunnel as replacement to pads also possible.

There are room for wheels as well as the caterpillar tracks on the cylinder to encourage

movement....