I could see challenging keelboat with your experience, but would highly recommend taking a coastal cruising and bareboat course to fill any knowledge/skill gaps that I am sure exist AND gain critical experience on a heavier displacement boat. Safety and confidence if nothing else. Plus respect for the company or owner of the boat you plan on chartering. Dinghies have little relation to bareboating in my opinion. Having more than adequate time training/practicing on a similar boat you plan on chartering is key.