Even without the simoleons from diving work going towards the diving job, it's still a good way to earn money. I got 16,000 simoleons just by delivering 2 eels, I was pretty shocked to be honest. My sim also won a fight with a shark, and as Pam said, she received the pumped moodlet and a shark's tooth appeared in her inventory which was pretty good as it was the last shell I needed. I must say, I am loving the scuba diving skill, even snorkelling is pretty good for killing a few sim hours, it's relaxing to watch.