Dude,
There are very few absolutes.
It depends on the boat, the weather, how many divers you have (e.g. can you fill the boat with your own bunch of divers), and what you want to do - which wrecks you want to dive. (Among other criteria.)
You may have to dive with another bunch of divers first, to show the captain that you are not an amusement park underwater and a yard sale on deck, but once you've established your bona fides you will be able to find boats that will go where you want to go. You simply need to figure out what it takes to get the captain to take you there.
Hint: No captains, or darned few, want to mix rec and tech. It's a sure fire way to ensure that NO one is satisfied with the dives. A rec bunch can be done with two dives AND a 2 hr surface interval in four hours or (often) less. Depending on the length of the transit, a boat captain can go out twice in one day. A tech bunch will take substantially longer to do the same thing plus the boat weighs more with all the scooters and sling tanks and assorted BS, cutting into profits, even compared to the cost of the extra fuel for the second run of rec divers. The captain needs to charge more to make it worth his while, plus he will often need a mate.
So if you want to charter a boat to dive the way you want to dive, step one is start working to find a satisfactory group of like-minded divers to give you a shot at filling the boat. Sixpacks work quite nicely in this regard... Then recognize that it will be more expensive and be willing to pony up group deposits in advance.
Best,
Doc