I knew I wanted to come back and do this route solo after the first time I did it with Trever and Jason.
I considered doing this route unsupported, which meant carrying my helmet the whole time or not using one at all. However, knowing myself and how frequently I hit my head on a regular basis, I decided to play it safe and just use a helmet. After much consideration, I also decided that I didn't want to run with a helmet for 15 miles. I stashed my helmet and headlamp under a bush at the start of the bushwhacking section, and I stashed my running pack under a bush near the visitor's center.
After jogging down the initial gravel road section, I turned off at a pre-marked spot along the road and snagged my helmet and headlamp. I put the helmet on for the bushwhacking section through the lava, spiky plants, and copious deadfall. It actually came in handy as I was able to put my head down and push through sections of thick brush. Despite the helmet, long sleeves, and long pants, I still ended up with numerous new scratches and plenty of sticks/moss/leaves in my hair.
My biggest concern for the day was the possibility of getting turned around or taking a wrong turn in the caves, but my memory served me well and I made it through the cave section without issue. The low ceilings made me grateful for the helmet, and the air in the caves is always pleasantly cool - a nice break from the heat of the day. I do highly recommend rehearsing the cave section prior to taking on this route (GPX track won't cut it because GPS doesn't work underground).
When I got to the visitor's center, I stashed my helmet and headlamp and grabbed my pack, then was off for the sandy trail section. This went fairly smoothly, but sand always takes a little extra effort, so towards the finish I was getting that "is this ever going to end" feeling.
This route definitely has the potential of going a lot faster. It's super fun and unique with the combination of bushwhacking, caves, and sandy trails. The views are pretty great and there is an abundance of wildlife.