DPVs usually is a "cave country" thing. I can't remember anyone would rent them from open waters operators. DPVs are a liability and f-ing expensive.
The liability is that the DPV can take a diver against his wish too shallow or too deep, too far, etc. Plus, if one puts fingers by accident into the propeller, there will be damage, depending on the DPV's torque. As you see, not a good mix of possible fatal accidents to offer for rent. Very unsafe, specifically for those who don't have a DPV experience. But how can you learn, if you can't rent? Buy? So, it is a chicken or the egg issue.
However, I seen in Fort Lauderdale some business
https://www.flbeachventures.com/ that rents SEABOB and takes a number of people to a shallow reef, no scuba, just freediving. You could instead offer something like that. Kinda similar to a DPV, only you hold on to SEABOB for dear life with a hand grip and hands get tired eventually. Unlike DPV that drags you by your butt.
Or buy your own DPV, tons of fun: