underseas tunnel with slope

[ElectroCyber]

hello everyone..

The new feature "overseas tunnel" was another cool thing in recent version Simutrans.
But, when i playing around with this, i found that underground view with water (sea) being unrealistic.
The railway track was laying down straightly above the sea level. Commonly, an underseas tunnel will be built under the seabed. I refers to the famous "Strait of Dover" tunnel between England and French , wikipedia link http://en.wikipedia.org/wiki/Strait_of_Dover.

So i have an idea to make slopes underground before the sea tiles.
Please see images below.

us (site down, do not visit) ]/image/show/sMy0tqz5Wp/undersea-slope-tunnel-1.png]
straight track above sea level

us (site down, do not visit) ]/image/show/wf4IwCfFxo/undersea-slope-tunnel-2.png]
what about slopes?

us (site down, do not visit) ]/image/show/2067WXrqef/undersea-slope-tunnel-7.png]
alternative #1

us (site down, do not visit) ]/image/show/yCWAhsHNDW/undersea-slope-tunnel-4.png]
alternative #2

us (site down, do not visit) ]/image/show/fDy7jhx-QA/undersea-slope-tunnel-6.png]
alternative #3

Or, maybe someone else got better ideas?

Just an idea,...  

[rsdworker]

looks nice - its would be useful with split levels mode

[Dwachs]

You can built tunnels under sea in recent nightly versions. Furthermore, you are not allowed to built tunnels through the open sea, otherwise this will be a bug.

Please check a newer nightly.