Late last year there was a History Channel special in which James Cameron goes down to a spot some distance from the wreck and finds part of the ship's 'broken back'
To go 600 feet as some survivors recalled, would have taken 20 to 30 hard pulls--enough effort to work up a sweat even on a cold night. Nobody describes working that hard at rowing. The boats were probably closer to the ship than they said. This means they really did not have to "go back," but were actually in the thick of the action already.
Based on the stopped personal timepieces of Thayer and Gracie, and the time of sinking taken by stewardess Robinson, there is an approximate 5 to 7 minute time period in from when the last of the lights went out to the disappearance of the stern from beneath baker Joughin's feet.
As far as Titanic goes, if what I've read about cold water immersion is true, the shouting would have subsided rather quickly--within a few minutes--of when the ship disappeared.
Wasn't he featured as a guest, though?
Also, wasn't John Jacob Astor's watch found on him with his body was pulled out? (His body was recovered, right?)