I’ve done charters all over the South (The Caronlina’s, GA, FL, Keys, etc) as with most of the above posters stated, the DM stays on the boat to help divers on and off the boat. The only places I’ve been that had tours guided by the DM’s/Instructors was in the Bahamas with Stuart Cove’s and at Coco Cay with Royal Caribbean because it was a "guided tour." I’m sure there are many others, but those are the only ones I’ve done personally.