The Sea to Summit of Kohala was one of the most enjoyable runs I have done on the Big Island. On May 27th, 2019 it took 5:54:19 to cover the 16.2 miles and 5,730 feet of elevation gain needed to reach the summit from Spencer Beach. The run really separates itself from the other volcanoes since the slowest and most complicated part is route finding through a dense rain forest to reach its summit.
From Spencer Park Beach you run a paved road with a pretty even grade of 5% for 12 miles. You then transition to a crazy steep pasture road with an average grade of 15.7% for 1.75 miles. Then everything slows down as you pick your way through tall grass along a treeline for around a mile. Then the fun begins and you step over a stile and into a dense rainforest for the remaining 1.6 miles (or more - depending on your route finding skills). Even the summit is a lush jungle so finding the highest point is entertaining. I detail this more in my trip report:
https://www.lifeintraining.com/ultrarunning/trip-report-sea-to-summit-kohala-from-spencer-beach-park