Maizuru to Kyoto for day trip

Hello,
My elderly parents will be arriving by cruise ship to Maizuru Port for one day, from 6AM to 8PM and wish to visit Kyoto for the day. they would like to then get on a sightseeing bus or train to visit places in Kyoto. they can't walk long distances due to their age. Can someone please tell me the best way for them to do this? I was thinking an area rail pass might be a cheap option for them, but I am not sure is they can catch a train from Maizuru with it, or if they have to buy a normal train ticket.
Thanks for any advice.

From JR Higashi Maizuru station to Kyoto=102.6 km on JR Maizuru Line, 135 Minutes.Taxi is more expensive.They can Buy JR Kansai Area Pass 1 day=2300 yen.I think JR is the best option.

https://www.whatsinport.com/Maizuru.htm - If you will be arriving in international terminal, it says here you have to walk or take a cab to Nishi-Maizuru Station.

From Nishi-Maizuru Station, there is Maizuru Limited Express bound for Kyoto but leaves every 2 hours. If Hyperdia is correct this time, the first one will leave at 6:47, next is 8:32.

There is also bus but not exactly sure about the starting point: http://www.kyotokotsu.jp/highway/course/maizuru-kyoto.html.

For the sightseeing bus, I found these links:
http://www.kyoto-regulartourbus.com/e/course/
http://www.kyoto-lab.jp/kloop/index_e.html

From Nishimaizuru to Kyoto

http://www.goo.gl/JF0zKu

Take Routes 1, 2, or 5 depending on the starting time. Print this page and show it at the ticket booth in Nishimaizuru station. You can buy round-trip ticket at Nishimaizuru, though there is no discount for the round trip, just for convenience.

From Kyoto to Nishimaizuru
http://www.goo.gl/UCvKY3

Take route 1.
There is no rail pass suitable for this itinerary. Just buy round trip ticket (6,300 yen).

Your parents will have 6 to 8 hours in Kyoto. Of course it is not enough time to see entire Kyoto, but I think they will experience something.

Thank you all for your suggestions. I am going through them one by one and discussing each option with my parents. Your suggestions are very helpful. I am sure they will enjoy themselves in Kyoto, immensely.

Cheers and thanks again
Coralie. :D