Chinoike and Umi Jigoku in Beppu

Hello
I appreciate some help on how to get to the above 2 hells.
I will reach JR Kamegawa station.
From there, I intend to walk (duration 30min) to Chinoike Jigoku.
From Chinoike Jigoku, anybody can advise how to walk to Umi Jigoku? Otherwise, is the Kamenoi Bus 16 or 16A the right one to take to get to Umi Jigoku from Chinoike Jigoku?
From Umi Jigoku, I intend to walk (duration 30min) to JR Beppudaigaku Station.
Appreciate comments from those who have done a similar walking trail, please.
Thank you.

It's better to take the bus. I don't remember the bus number, but the timetable should be posted at the bus stop. You can also ask the staff at the gift shop.

I've tried walking from the Kannawa area hells to Chinoike jigoku. It's definitely walking distance, but the road is not very well marked, a section lacks sidewalks, and there is a tunnel. At this point I was offered a ride by a passerby, and gladly accepted!

Yes, I figure that it is better to take a bus.

Can anybody who reads Japanese help me, please?

I found the bus schedule for Kamenoi bus:
http://www.kamenoibus.com/

My date of travelling is 3 Nov which is a public holiday.

May I confirm the bus & timing:
1) Kamegawa Stn to Chinoike jigoku:
bus 26 or 26A, departs from ths Stn at 0818 and 0848.
2) Chinoike jigoku to Kannawa bus stop for Umi jigoku:
bus 26 or 26A, departs from Kannawa bus stop at 1013
3) Kannawa bus stop to Beppudaigaku Stn:
bus 20, departs from Kannawa bus stop at 1119.
Many thanks.

May I ask what is the difference between bus 26 and bus 26A?