I will offer my two cents:
1. Some will disagree after much experience towing dinghies, but I do not recommend it.
2. The key is to develop a good system to hoist and secure the dinghy on the davits so that you can do it with a minimum of time and fuss. The harder it is to do, the more likely you are to take the shortcut of towing.
3. I will admit to towing our 9.5 ft Achilles with the 9.9 HP 4-stroke attached for up to 10 miles in very calm conditions. I did that partly to be lazy and partly to see how the dinghy would tow astern of the PDQ. For that one-time experiment, I simply had one painter from the centerline eye bolt to a stern cleat. It rode fine in calm conditions at 7 kts with the engine tilted up.
4. I have seen large vessels (100+ feet) towing 24-foot fishing boats at 20 kts or more on a very long line. I would not wish to try towing my dinghy above 7 kts, but surely it can be done, although at much greater risk to capsize, I would think.
Perhaps others who favor towing can chime in with practical advice for you.
m/v Diva Di
Punta Gorda, FL
2006 PDQ MV 34 - hull 91, 75HP, 3-blade