Hello Tammy,
On all the big liners I have sailed on dating back to the early 50's and after, a bridge Quartermaster took the wheel immediately the last line was cast off from the dockside. I would imagine that this was the procedure in Titanic's day also and if not, I'm yet to hear about it.
It is a misconception to think that the master or pilot takes the wheel during pilotage.
I've only known this to happen in very small craft or at ports of call with unusual tidal and current conditions. In such cases it is usually by request from the master or sometimes protocol of the local harbour authority.
It is also interesting to note that with Cunard White Star, the lookout also took his position in the ''nest'' on sailing but this wasn't the case with many other shipping company's who maintained the dusk to dawn routine.
To answer your question more fully, the Quartermasters would then operate their usual watch routines throughout the voyage of 12-4, 4-8 and 8-12 etc.
I hope this is what you're looking for,
All the best
David