Hiring Lookouts

I am curious to know how lookouts were hired in the White Star Line. I read the following in the US Inquiry:

Senator Smith: "Are experienced men usually selected for the lookouts?"
Mr. Lightoller: "Speaking for myself, I always select old lookout men that I know..."

And in one of Mr. Fleet's letters he says that he "stayed awhile in [Oceanic] then transfer[red] to the Titanic."

I know that Mr. Lightoller had been an officer on the Oceanic and that Symons and Fleet had both been lookouts on that ship for a couple of years. Would the "old lookout men" have been transferred to the new ship on the recommendation of one of the officers, or how was it that they were later employed on the Titanic?