I am not with the OP on this one, at all.
First, you put divers in the water who are diving and surfacing without a dive flag. They have an "orange float" which means and signifies nothing to boaters and is probably not even visible until the last second. So, you have no right to expect other boats to avoid the area, and no right to harass other boats in the area when you don't have the common sense and consideration--let alone your legal obligation--to signal them with the universally recognized flag that divers are present. How do you motivate the boats to avoid the area where you have divers operating basically in secretdo you threaten to ram them or approach as if you intend to do so, forcing them to change course?
As for the scuba divers, who were acting lawfully, had the proper equipment, and were within the legal distance of their flag, your attitude is incomprehensible. First, you had over 1/2 hour to watch their flag approaching and avoid it. It is nothing but an instant's work to have your freedivers get on board, avoid the scuba flag and circle back at the appropriate distance and jump in again. You were not stuck in your spot, unlike the scuba divers, who have no such mobility at all. There is lots of reef around Horseshoe, as you know. Bottom line--their flag gave them the right-of-way and an expectation of safety and respect.
Even worse, you revved your engine--how are they to know you were not in gear or are about to get in gear at high speed due to the revving? What on earth else does revving signal? Is this part of your motivation routine? Your actions were not only illegal but threatening as well. The other skippers reaction of asking the diver closest to him why is he doing that is perfectly understandable. Your comment that it the diver wasnt revving, ha ha makes you look even more ignorant of how wrong you were.
If you had a proper diver down flag, that might have at least alerted the other boat that other divers were in the area and some radio coordination might have been needed or (with you being there first) he might have called his divers up.
Your actions were not reasonable. It is only if navigational exigencies such as confined space or extreme currents force you within 300 feet of the flag, then you proceed at idle. No such existed in your case. You had no flag. You had no right of way. You had surface divers that are easy to get into your boat and avoid the flag at the proper distance. You had plenty of time. Maximizing your spearing catch is not a reasonable reason to disregard a dive flag. You actually do not have just as much right to the reef if you do not display a flag.
If the FWC had been there, the divers with lobster gear would have gotten a nice fine. You would have not fared any better, though, hopefully.
Your attitude that you own the ocean without complying with law, that you are Wyatt Earp and Rambo rolled into one, that law abiding divers are contemptible, that other boats and divers are targets for a game of chicken and threats, and, worst of all, that you do not even care enough to properly mark your own divers, makes you, not others, the problem.