Captain Smith released the two Marconi operators directly. He didn't have a quartermaster do it, or even a jr. officer. He personally walked/ran to their room and told them they were to look out for themselves from that point on. Indicating that Smith had come to a final conclusion about the fate of Titanic. His coming to such a conclusion tells me that he was in a state of ongoing evaluation of the ship's situation. Not a state of disorientation or disassociation.
Smith didn't know for certain how long the ship would float or be able to sustain life aboard it. He did know that eventually she would sink. In Smith's mind, Titanic might be somehow float for several hours before disappearing. How could he know for sure? As long as Smith had reason to believe that Titanic was able to sustain life, he was required to try to direct his crew in efforts to combat the flooding, keep the power on, call for help, and maintain order. Why would Smith take it as gospel that the ship would sink in less than two hours. Who knew for certain Titanic couldn't somehow float until morning despite the dire predictions. Smith didn't know as much about Titanic as we do. He didn't know the rate of flooding. As long as the ship is able to sustain life, it makes sense that he would desire his crew to perform their duty and see to the care of the passengers, and try to maintain the stability of the ship as long as possible. Every hour the crew can keep Titanic stable and afloat, even if they are fighting a loosing battle, is an hour less everyone will spend in the water until help does finally arrive. Every minute counted and Smith knew this. In short, what sense does it make for a captain to give up on his command just because he's told the ship is doomed. It doesn't. Especially not when half an hour after the collision his vessel is on a relatively even keel, in flat calm seas, and in clear weather. And add to that he knows help is on the way. He can even see lights on the horizon. Surely the logical conclusion at that point is for him to direct his crew to fight to keep the ship afloat at all costs to equipment, and property. Not to simply turn to his first officer and say,'Well we're sunk. Abandon ship, and good luck ol' boy. I'll be lingering about slipping into a state of mental debilitaion.' I don't think so. Smith fought on to preserve his ship as long as possible. And he maintained a watchful monitoring of the situation. The question on his mind was likely, 'How long can we last before we loose her?', and 'What else can we do to hold on to her?' Today we know they managed to keep her mostly above the waves for 21/2 hours. Actually almost an hour longer than was predicted. While the crew frantically fought the force of the Atlantic, Smith watched, took in information, felt, listened, judged.
But then the ship finally began to tip and started its death throws. Smith certainly determined in his expert eye that the fight was over and no more efforts by his crew could prolong the stability of the ship. At this point he did his final duty which was to release his crew from their duty to him and instruct them to do whatever they could to save themselves. Having issued a command of 'every man for himself', or something to that effect, he then was left to deal with his own fate.
He could have retired to his cabin for a smoke. Or he could have put a pistol to his head. But he didn't.
For reasons we shall never know or understand, Smith dove into the water and into the realm of legend.