Of all the tools at Ahab's disposal in his vendetta, men are the tools most apt to get out of order. The most likely of all would be Chief Mate Starbuck whom Ahab knew to be against the vengeful pursuit of Moby Dick, to the dereliction of their duty to the whaleship owners. The "savage crew" was easy for Ahab to sway, and he even brought Starbuck around; but Starbuck epitomizes the steadfast soul whose morality cannot be totally compromised, and Ahab knows it. Starbuck would be the most likely to relapse into rebellion against Ahab should a long wait be endured before the white whale is sighted. Therefore Ahab must be patient, allowing the whaling voyage to proceed in the usual way, until his chance at Moby Dick presents itself.
Regarding the crew, Ahab had best consider another problem. Fired up though they may be to hunt and destroy this thing of evil that their captain has conjured up in their minds, hearts, and souls, still the realization that their cash compensation can only come from sperm oil in the barrels down in the hold will dawn on them sooner or later. Melville makes the invidious comparison to the "high lifted and chivalric Crusaders" who had to divert themselves with burglaries, picking pockets, and worse for diversion on their way to rescuing the Holy Land from the infidels. Ahab will bribe the crew with much more than a single gold coin in later chapters.
The most serious worry of all for Captain Ahab was that by declaring, "And this is what ye have shipped for men. . ." when revealing his intention to chase Moby around the world, he had "laid himself open to the unanswerable charge of usurpation, and with perfect impunity his crew could refuse all further obedience to him -- and even violently wrest from him the command."
"Ahab must of course have been most anxious to protect himself. For all these reasons, then, Ahab plainly saw he must continue true to the natural, nominal purpose of the Pequod's voyage. And not only that, but force himself to evince all his well known passionate interest in the general pursuit of his profession." In other words, put on an act -- make believe that he is not a raving maniac bent on dragging the whole ship and crew to perdition, while everyone else is pursuing the ordinary business of whaling.
And so, "His voice was now often heard hailing the three mast-heads and admonishing them to keep a bright look-out, and not omit reporting even a porpoise [dolphin]. This vigilance was not long without reward."