The trail down is easy but going back up will take awhile and you need to be in decent physical shape. Take plenty of water and of course use bug spray. For my money, the NPS trip is worth every penny. Parking at the trail head is very limited and I always drive past it the first time. You hike the easy part (down hill) get some interesting history and local knowledge but the best part is avoiding the hike back up. The ferry ride back can be a little rough so if you do get motion sick, bring some meds.

The NPS tour with the taxi up and boat back is a bargain - tennis shoes are fine (with some grip) - not a tough hike - very but hot/humid in June - bring plenty of water and a snack. A definite must do.

You can access the petroglyphs from the bottom as well if you take your own vessel into Reef Bay and use the mooring ball if it is open. The ranger led trip is xtra informative and really the hike down / boatride back NPS combo is well worth it. Not generally buggy and just wear good shoes,not open toe. It is safe and easy to follow on your own.

If you are in any kind of reasonable shape you are going to find the NPS led hike pretty slow. Its a pretty easy walk down. The walk up is steepest at the end. I have no problem doing this in Tevas.

Cheers, RickG