The series of tutorials I'm watching sets velocity directly on the object - the script reference on Unity's homepage says to not do that. Hmm... :) blog comments powered by Disqus
The difference I suspect lies in whether you are making something arcadey or something vaguely based on the physical world - if you want physical interactions you have to obey certain rules so that the physics knows how to react. If you set the velocity on an object directly it's somewhat akin to magic - objects don't just gain speed from nowhere.
I suspect I'm going to have to investigate the AddForce function, which will properly give me acceleration and eventually velocity, if I want to do this right (I do, since feel is a huge part of driving something huge through water). That's how you actually achieve a velocity - by applying a force against countering drag and inertia.
But that's for later. First I must try and figure out how to rotate the ship. I suspect that, again, using "rotation" is a no-no - I have to AddTorque instead and let the physical body of the sub be affected by it.
In conclusion: more tutorials!