Character Analysis
Lovett is described in the script as a "treasure hunter." But he's not some beachcomber with a metal detector. When the films open, he's working in the present to find a very expensive diamond called the Heart of the Ocean, which he had reason to believe was on the Titanic when it sank.
While trolling Titanic's wreckage, he locates the safe that belonged to the diamond's last known owner, Cal Hockley. Naturally, Lovett thinks he's hit the jackpot, telling the others:
BROCK: It's payday, boys.
However, the safe turns out to be empty except for a drawing of some naked woman wearing the necklace. He gets news of the drawing out there, and soon enough, Rose (at 100+ years old) is calling him up to let him know that she's the girl in the drawing.
Brock doesn't seem like a bad guy, really—but he's definitely got a one-track mind about getting the diamond, which makes him come off as a little greedy. He also seems a bit arrogant—after all, he was so confident that the diamond was going to be in Cal's safe that he busted out the champagne before the safe was even open.
That all said, we see a softer side of Lovett at the end of the film, when he's heard Rose's entire story.
He tells Rose's granddaughter, Lizzy, that for all the time he'd spent exploring and studying the Titanic, he'd never "let it in"—and by that, we assume he means the human impact of what had happened.
It had been all about the treasure hunt up to that point for him, but Rose's story really brought home how many people died as a result of Titanic's sinking. He's transformed, and as a result, seems like much less of a jerk when the movie closes.