Deception
Columbus records the state of affairs of the crew aboard his ship during the voyage. Apparently the captain and his men lied to the crew about how far they travelled each day in order to make them hopeful. Of course such a great secret was bound to be discovered. When they did learn the truth, the crew became incensed. They nearly hold a mutiny, but the captain changes their minds because they have nowhere else to turn for supplies since they're so close now. After this, the captain starts underestimating the distance reports so that the crew are kept guessing.
Greed
Columbus is first and foremost a businessman. He's made this entire expedition happen so that he can realize his dream of being rich and famous. His values are apparent from his writing. When he begins the journal, he explains that his intent is to keep a careful record of events to present to the King and Queen of Spain so that they may be impressed by the excitement of the trip. Each entry is crafted to yield as much excitement as possible; he's trying to hold interest over the course of a lengthy, boring journey. In America at last, Columbus can't stop talking about how thrilled he is to see such a vast, endless expanse of resources to exploit. He's thinking about monetary gain and eager to impress his investors.
Fear
There's some decided notes of fear in Columbus' entries as a result of the great among of ambition for the voyage. Nobody is certain of what they'll discover or even if there is any actual land to find. This becomes readily apparent once the ships enter uncharted waters. Driven crazy by the fear of the unknown, the crewmen also start to express their anxieties which are compounded by the captain's capricious nature. Unable to return without landing somewhere for supplies, they sail onwards into the unknown. The crew becomes so desperate that they threaten a mutiny. Unwilling to return to Spain with nothing to show his investors, Columbus makes a bargain with the crew that they'll turn around in two days if they don't find land within that time. Fortunately for him and for everybody on board, they do that very thing.
Excitement
Columbus' journal is an adventure story. He's certainly excited about the trip and it's untouchable potential. In writing his entries he takes great care to make them as interesting as possible. After all he's trying to impress some extremely powerful monarchs. This leads him to point out every animal, stick, and star which anyone on board observes. He's being thorough, but more importantly he's demonstrating his enthusiasm and gratitude for the trip.
