[kens]

I haven't looked at submarine systems in detail, but my understanding is that the big problem is that an ICBM knows where it's starting, but the submarine travels. So submarines have super-accurate inertial navigation systems on board to determine their position.

[ethbr1]

I was thinking more for the sequence where it broaches the surface then lights its engine.

https://m.youtube.com/watch?v=h5KejRbD5s0&t=34s

That's a lot more dynamic of a launch orientation. Which way is it rotated? Is it inclined off vertical?