Excellent report as usual - sorry I missed your PM before the trip; I would have offered to tag along but after reading this thread I realized that the weather was indeed lousy that weekend. I was supposed to be diving on a friend's boat in the area April 30 and we had to cancel.
I will make one correction to the list of dive charters; I believe Jim Abernathy's Scuba Advantures stopped doing Palm Beach baited shark dives when he sold the Deep Obsession to Ryan Walton as it's own independent charter. JASA still does standard Palm Beach dives; last I checked they were still doing baited trips to the Bahamas. That makes for three SCUBA operations doing baited charters in Palm Beach County waters - Emerald, Calypso, and Deep Obsession. Of the three it's worth noting that Emerald is the only one operating out of Jupiter Inlet; the other two are based out of Lake Park Marina and leave from Lake Worth Inlet. That affects transit times and also is a factor when weather is an issue. On the snorkel side, I believe there are a couple other options in addition to Florida Shark Diving, although I'm not sure of their status.
The bit about the 120s is new - the last time I was on the boat in February nobody barked about my two "water heaters" (LP 120s). I used to rent HP 120s from Scuba Works and stopped doing that because it was really more gas than I needed, except for when I'd take the first ten minutes or so on the Deep Ledge to strafe lionfish at 120-130. The other issue with big tanks is with the possible exception of short, fat HP tanks like the Fabers it's really difficult to bungee them into the Emerald's racks - for my LP 120s I started bringing some of my own bungee cords to lash them in.
Spot-on with the shark notes. Generally the lemons will swarm the group, but they're interested in the goodies the feeder is carrying. If anything you have to make sure you don't get too complacent with them; they still have teeth. One in particular to keep an eye out for is a resident female known as "Two Scar" or "Stevie" depending on the charter; one eye is obviously blind and she'll sometimes bump into people on that side. Back in January I felt something hit the Manta reel I keep clipped to my hip; it's an exercise in maintaining calm when one sees the source of the bump is an ~8 ft half-blind lemon shark with her nose uncomfortably close to your crotch.
The tigers on the other hand demand your respect; as predators their MO is to get really close without being seen. I'm often impressed at how well that camoflage works; at times I've actually seen their shadow on the bottom before I made out the shark above it. They're the ones that I really feel are paying attention to where you're looking. That said, I've never felt they were out to take a piece of me - it's more like they're just seeing what they can get away with. Keep your eyes on them and it's not an issue. The fun thing I like about the tigers is that all three of the ones you saw were repeat customers - Patrick is the new kid on the block from last year and our only recurring male; the first visual record I've seen of Sassy Cassie was from one of Florida Shark Diving's videos in 2015, and DJenny is currently the long-running champ having turned up every year from 2014 to now. After that much time you start to notice they really are individuals; Patrick is fairly easygoing, Sassy Cassie is curious but really wants the food (I'll frequently see her trying to jam the entire crate in her mouth), and DJenny is like the "clever girl" from Jurassic Park that'll have you looking in all directions.
Bulls generally have two settings - on or off. The majority of the time, they stay away from the divers - one reason why you're advised to stay at the DM's level or above is that dropping down below the group forces the bulls deeper. The few times I've seen them mix it up with the group, it's been in lower-visibility conditions. Obviously, there's plenty of accounts and footage of them getting very up-close-and-personal around freedivers and spearfishers.
Overall, glad you had a fun trip even with some weather issues - I remember when I first got into diving sharks were something I always wanted to see and even a lousy nurse shark was cause for excitement. Now I have a chance to see multiple species in one day just a couple hours up the road, and have gone across to do Tiger Beach twice.